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Messages - DesertDragon

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51
General Motorcycle Discussion / Re: More Fun with Fuel....
« on: September 03, 2017, 09:17:23 AM »
I can say I've never tried it.  Thought there was no point.  I would bet though that premium where I live would still have ethanol in it.  But for the sake of an experiment I'll try it.  I am confused about your use of the word octane.  Most of what you are describing would be accomplished by jetting.  Elevation, air temperature, anything that changes the air density will change the air/fuel ratio.  I've never heard of someone compensating for altitude changes with different octanes.  You would use different jets.  I'm curious about your bike DD.  Is it completely stock? Any jet changes or shims under the needles?  The late hawk is said to be lean from the factory.  Is the super somehow compensating for the lean A/F mix?  That would explain it.  If an engine was running lean and all of the sudden was running right you would get everything you describe.  I don't know if thats possible and you guys are diving deeper into this topic than I'm capable of.  Up until now my only thought of premium was some engines like it, some engines don't care.  Figure out what your engine likes and run that. 
You make some good points, and like you, I had never tried super either because I "knew" it wouldn't make a difference.
It was actually a guy on this forum that used it and seemed to have noticed results, so I tried it myself as an experiment.

"Octane" as used to describe a fuel rating, is actually an anti-knock index. It just happens to be one of the only easily identifiable qualifiers on fuel.  Ethanol is another, but you typically don't have a choice - Most metro areas use it ubiquitously.  I'm not sure if that also allies to super.
I live in a rural area, which doesn't have the same mandates as most cities do.
 
My bike is internally stock.  The air cleaner is stock in dimension, but a cleanable UNI which is likely breathing better than the stock paper.
That might cause the mix to be a bit leaner.. No other engine mods.  Carbs were rebuilt (gummed up from sitting - won't do THAT again) but they were reset to how they were. 
I didn't notice a difference afterwards.  I had not heard about the "lean 'Hawk"... Could be a factor. 
That might make sense if super "acts" like a "richer" fuel.  Maybe somebody can comment on that...
While perhaps the same results could be had with jet mods, there is no way I'm going to open up a "golden goose" to find out.
My scooter is running sweet, and since it "ain't broke"... 
 ridn2
I have always sought to understand things that I can't readily explain, but maybe this is one of those that prefers not to be known. 
I can live with that, and in any case, I'm happy with how the bike is running, especially my 51 mpg!

I like your last line, and that may be as close as I can get to an answer.. At least it's pragmatic.
I guess my engine "likes" super, some others like it, and still some others will find that their's don't care..

I'll be looking for your result, or not result...
 bkr3


52
General Motorcycle Discussion / Re: More Fun with Fuel....
« on: September 02, 2017, 06:25:27 PM »
Larry - Good post...
I had an 82 GS 750EZ with TSCC - I loved that bike.
As far as the fuel....
I'm trying to understand, by thinking out loud, reading replies, and reading LOTS of other stuff with varying opinions, what is going on in my engine. 
I started all of this with an expectation that changing fuel grades would result in a big NADA - The exception being the cost difference between super and regular... 
But that's not what happened.
I know how an engine works, but I liked your explanation of the combustion phase.

For most folks I would agree that regular is a better choice. 
I wouldn't consider it for my car, but then it also water cooled, has a computer controlling it, has relatively low compression and runs fine on regular.
My bike is pretty much opposite of that, and although I didn't know it, or anticipate it at the time, they way it acts with super has been better.
It warms up faster, I can take off sooner without stumbling at low RPMs, I can run it all the way through to red-line without a burble like I had before, and to boot, I got better mpg than with regular. 

Regardless of the specific reason(s) for this, something is going on. 
My rifle vs cylinder example was an attempt at a possible explanation, because something is happening. 
Maybe it's a lot of somethings.

While both the too fast and too slow fuel burn phenomena are possible, all other things being equal, something caused my rpm at idle to increase. 
You would not expect to have waste cause an improvement, and I don't see that as being likely in my engine.

Could it be possible that it's ONLY my engine... Anything is possible, but several other folks have commented with similar results so I doubt it.
That's why I thought it might be interesting to find out results from other folks experiments.

Mechanically, my bike was and is in great shape. I went through a recent major tune, and have a newly cleaned air filter.
It has like new compression, and I was getting a consistent 45 mpg until I switched to super.  Now the mpg is over 50.
That's an 11 percent increase...  Will others see this.. Maybe.. Maybe not...

I would think an inexpensive and very easy test, by grabbing the "other" pump handle would be worth the possibility of having a machine that "worked" better with the more expensive fuel.  To me, it isn't even more expensive as the fuel cost and mileage are a wash.
The difference in how the bike runs makes it worthwhile for me.  For someone else, maybe not.  Maybe it would be worse.
I don't know, but I also never claimed that everyone would notice the improvements that I did - I just suggested they try it.

Apparently, fuel and oil and tires and just about everything else on a bike are topics where strong opinions are held.
Everyone is entitled to their own opinion, but if that opinion prevents them from trying something that might be good...

Anyway, whether or not you notice a difference in the positive, negative or none at all, please do post it.

53
General Motorcycle Discussion / Re: Exxon Mobil SYNERGY Gas
« on: September 02, 2017, 11:31:23 AM »
I have used this gas in my cage and my CTX700 with no issues. I find this gas is a bit better than the other gasses offered in the area where I live. I think it also comes down to the amount of ethanol the put into to gas when it is prepared to go into the tanker truck for delivery to the gas station.  Once I get my Night Hawk back in working order, I will definitely give this gas a chance to see how well it performs. 
I tend to agree as far as ethanol goes - Look at the "fun with fuel" thread...

54
General Motorcycle Discussion / Re: More Fun with Fuel....
« on: September 02, 2017, 10:08:34 AM »
Larry, you make some good points, especially the "dilution" factor...
As far as a faster burn = more power.... Here's another take, from an optimized shooting perspective.
Different gunpowders, like gasoline grades, have different burn rates.
Very fast burning powders (like regular in your post) improves performance in a short barrel where there is a relatively short run to accelerate the projectile.
In a longer barrel, the same fast burning powder will not produce as much thrust as a slower burning powder, and although the differences would seem to be relatively minor, there are major measurable results between the two.
The reason the slower burn results in a faster projectile in a longer barrel, is that the bullet is being accelerated down the entire length of the barrel.
If the "burn" stops before the bullet exits, the gas pressure begins to lower and the remaining length of the barrel is actually serving to slow down the bullet through the remainder of its travel.
If you think about it, a gun and a motorcycle cylinder are not all that different, in regards to both being powered by a controlled explosion driving an object through a sealed space.
While the faster burn may have more initial pop - It is the total force applied over the length of the barrel (gun or cylinder) that results in power.
When you mention "smoother", and I've noticed this as well, it may well be that the bike "likes" a slower burn fuel, and rather than a quicker "pop", it is getting a longer "push"...  If the engine is taking advantage of this difference, it well could be a major component of reason I noticed a mpg increase.
It would also seem to explain why several people, myself included, noticed an idle speed increase with super.
If the same amount of fuel is delivered to the same engine and it begins running faster (increased RPM), it MUST have gained some efficiency.
I would be interested to hear an alternative explanation for this observation, but I doubt it would be one that made sense.  It's just physics.
Your comment made me think of one other fuel related item... 
When the Nighthawks were originally produced, ethanol was a much less common ingredient in regular grade fuel than it is today.
While the regular "octane rating" may be the same (~87) the addition of ethanol, which effectively increases the "octane number" may have changed the characteristics of the fuel burn rate enough that the engine is not operating effectively with the "regular/ethanol" fuel mix...
Thanks for getting me thinking... The ethanol/not difference may well be what's going on here...



55
Your Honda Nighthawk / Re: First time rider!
« on: September 01, 2017, 07:10:15 PM »
Wow - First time rider and you managed to select the best motorcycle ever made!
Good job.
I've had my 96 for 11 years and it's never left me stranded.
You also found a great forum - There are some very knowledgeable and helpful folks on here.

Enjoy the ride!

56
General Motorcycle Discussion / Re: More Fun with Fuel....
« on: September 01, 2017, 06:55:12 PM »
Pretty good post. I've done this several times over the years in my VFR and seen ZERO difference. BUT ... Just for gits and shiggles I'll try it next fill up in the Nighthawk and let you know.
As the Captain said... EFI - Keyword there is electronic. 
Don't know specifics of the ECM (engine control module) in your VFR, but you have one, and it likely will automatically alter timing to ensure that it is doing what its designer intended. With enough data (and you already added some) my hypothesis is that the more intelligent the machine, the less benefit from a higher grade fuel, except for those that NEED it..
But - In a dinosaur, like I am proud to ride, the upgrade makes a difference (well, I've convinced myself already based on observation).
Take note before you dump some super in there, how long it takes to warm up. and how it takes off from idle when "cold" (relatively).
Compare that to the next day with super in the tank.  That's the first thing that struck me.

Enjoy the ride...

57
General Motorcycle Discussion / More Fun with Fuel....
« on: September 01, 2017, 11:31:06 AM »
Howdy..
After a member's thread on "real or placebo" for a fuel switch prompted a lot of conversation, it got me to try super in my bike.
I noticed some positive differences in the fuel switch for my 96 750 from Mobil regular to Mobil super...
Quicker warm up, increase in idle speed, elimination of "stumble" near redline, and an improvement in mpg was what I noticed.
Some of this can be explained, and some seems to be a mystery and/or flys in the face of "consensus" opinion.
 
Between rides, I've been doing a lot of research, and it is amazing just how much controversy there is on the regular/super topic beyond this forum.

I did learn a few things.  Read on if you're interested.

Octane rating:
One of the few things you can tell about a fuel by looking at the gas pump.
Also one of the things that is tested, that must conform with reality.
A surprise to me, is that "octane rating" is NOT equivalent to, or a measure of "octane content".. e.g. super grade with a rating of 93 does not (necessarily) mean that it contains more octane than the fuel from the next pump displaying 87. 
What it DOES mean is that the super/premium rated at 93 "acts" like it has a higher octane content when measured.
This can be due to actual octane content in the fuel, one or more of a large number of base stock combinations, additive additions, displayed components (typically ethanol / mtbe) mandated for emission purposes, or substances included for engine improvement/advertising (Techroline?)
So, the "octane" rating is really not an "octane number" at all - It is called an anti-knock index (in the fine print), because that's what it is.
Octane or "octane acting" components act to slow down the combustion process... (more push, less BANG)
It assists in prevention of premature ignition (knock) which can destroy an engine over time.
The "consensus" opinion with regards to "octane rating" therefore, is if you don't have knock from a given fuel, you don't "need" a higher rated fuel to prevent knock. 

Fuel formulation:
Although the octane index is not an octane measure, and more isn't necessarily better (unless you need it to prevent knock), the way that the fuels get to that number can be very different by fuel grade.  One of the major differences, is in the addition of alcohol (ethanol) to the fuel.
Although alcohol has less measured energy than "gasoline" (BTU/unit of measure) it will provide the fuel to which it is added a relatively higher octane rating.
Alcohol also burns hotter, absorbs water more readily, and evaporates more quickly at the same temperature than does "gasoline".

Ethanol is a very common regular unleaded additive, but NOT a universal premium fuel ingredient. 
Therefore, in addition to the higher rating, that extra 20 or 30 cents per gallon for super may be buying you more "actual" gasoline, rather than an alcohol/gasoline mix.

Engine Control:
One of the primary cited reasons that "premium fuel" is a "waste" is because modern engines have computer controlled, multi-sensor systems that monitor both external environmental conditions and internal engine performance, and then dynamically modify engine operation based on sensor input to optimize for desired programmed factors (e.g. fuel economy/performance/emissions/etc). 
These systems can also allow an engine that would otherwise "knock" itself to death, run well, or at least acceptably well, with the same grade of fuel.

Engine types:
There is a considerable difference between an air cooled and water cooled engine in terms of their operational temperature, yep - air cooled engines run much hotter.  There is also more operational variation in them, as they don't have the mitigating factor of a water jacket surrounding them.
If you look at what's available out there - Lots more water cooled engines - Their operating temperatures can be modified (kick on the radiator fan) which is something an air cooled motor can't do.

How does this relate to using a "higher grade" fuel in the CB 750, and any actual or perceived improvement in performance....
While there is some pure opinion which follows, at this point, I think the following may be factors that align with my improvement observations...

Fuel Formulation:
Since the super I used didn't have ethanol in it, but the regular grade did, my Nighthawk, without any vapor recovery capability would lose more fuel to evaporation because the ethanol more easily evaporates.  Over time, this would mean there would be less fuel left to burn.
Alcohol also "loves" to absorb water, and the resulting regular fuel solution would contain more water (and less energy per unit volume) over time.
These factors may or may not be significant, but in my case, since I go on a large number of short trips (gas tank heated up each time) over an extended period of time (weeks), even small differences will add up.  All else being equal, these factors would serve to increase measured mpg.

Engine:
My CB 750, being air cooled, and therefore running hotter, especially in my high desert, high temperature environment, has an increased need for for a slower combustion process to run optimally.  The bike is not equipped to dynamically alter any performance characteristics beyond spark advance.
As temperatures increase, equivalent performance requires improved "octane" to maintain optimum performance. 
(this appears to be generally accepted, and is used in racing prep design calculations)
With regular fuel, the bike may not be knocking, but that doesn't mean it's running ideally either.
I did find an interesting fact for recommended fuel grade for The Harley.
With a lower compression ratio than the 'Hawk, but also equipped with an air cooled engine, their minimum recommendation is 91 (super).
The manufacturer rating requirement for a fuel grade cannot possibly address all possible conditions, but in my case, based on some performance curve calculations, the recommended fuel rating is apparently not sufficient for my engine's needs.  If it were, there could be no improvement.
Improvement was obvious to me, and apparently some others, and although I agree that "runs better" is a subjective assessment likely to be impacted by "placebo bias", when a significant change is measured, it's no longer subjective.
The most obvious change in performance for me, was near redline, which tends to require more help from the fuel in prevention of pre-ignition. 
I cannot think of any other reason why just a change in fuel eliminated a stumble if the lower grade was adequate....

Still interested? 
If you are willing to gamble a small wager (~$1 - $1.50) on a tank of fuel, see if it makes a difference for you.
Whatever you can measure, I'm interested to know your results, good, bad or no difference.

On the "placebo or real" thread, I mentioned that it might be an interesting experiment to capture results.
I'm thinking that brand, grade, octane rating and additive (ethanol and/or mtbe) of the fuel and your bike type would be a good start.

One benefit of participation...
 ridn2
You need to ride to find out if there's a difference!





 


58
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 30, 2017, 07:25:27 PM »
Sorry for my continued verbosity, and for any prior offense - especially to you Pants Man - I shouldn't be so passionate.. But I am..
 haphap
There is a lot more chaff than seed out there, but here are a few factors with some consensus I've been able to sift out so far...

Factors which increase engine fuel octane requirements:

* Compression: Higher engine compression ratios increase the engine's octane requirement (91-03 'hawks are 9.3 to 1)
* Temperature: Hotter air increases the engine's octane requirements
* Humidity: Drier air increases the engine's octane requirements
* As engine spark timing is increased, the octane requirement increases
* Driving method: Rapid acceleration and heavy loading increase the engine's octane requirement

Factors which decrease octane requirements:
* Altitude: Higher altitudes decrease your engine's octane requirements (and reduces effective compression)
* Modern Engine Control systems: Automatically compensate for nearly every factor

Looking at some very complex interactions, it appears that there is data to support the case why MY CB750 Nighthawk runs better on high octane fuel:

* Bike designed with (relatively) high compression engine
* My observed (adjusted) compression (see post in Engine Tab - Your bike's compression is better than you think) is close to factory spec ~ 185 +/- 5
* I ride in a very warm, dry environment (during testing period) > 90 F 10% RH
* Higher octane fuel performs better in full advance / high RPM situations - High speed full throttle performance improvement was noted
* My bike is carburated without engine control systems

I do live at altitude ~ 5000' which is a mitigation factor for octane need. 
My hypothesis is the other factors overcome this, to some extent.  (note: I'm NOT driving down into the heat to test this)

Based on these in totality, an effective octane rating for maximum performance for my bike in my environment is estimated between 91 and 93 - NOT 87.
Super (higher octane generally) fuel actually burns slower, but more effectively in the right cylinder, which may be a factor improving low rpm performance.
More effective burn will improve mileage through less fuel needed for a given rpm and cylinder charge.

I'm pretty sure another mystery - for me - Has been solved.

If you are driving a 'Hawk with good compression, in a warm environment "robustly", and especially if you are at relatively low altitude and humidity,
your ride may well benefit from an increase in octane that will be "noticed"....

If no factors apply, probably not (especially bikes with engine control systems).

There may well be other factors involved in fuel formulation components (or lack therof) / additive packages / alternative components (ethenol / MTBE) Etc... Etc... Etc....

This would be a candidate for a lot more input if there is an interest in experimentation.
In the meantime, it's summer, the weather is nice so go for a ride, check it out for yourself and see if you notice a difference...
It will cost you nearly a whole dollar for a tank.... Or don't.

Regards to All

59
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 30, 2017, 05:23:45 PM »
I'm too cool (i.e., lazy) to keep records, but I am willing to try a tank or few of BP/Amoco regular grade and report any noticeable changes. I figure changing grade and nothing else should point to octane reduction only, presuming otherwise-equal formulation.
Thanks for the offer to step up, and yes - See what happens. 
So, you already use super in your bike.... If so a single tank won't hurt and maybe save you a $1..
Please try to be aware that there is a possibility of bias..
Based on what you've read here, you may "expect" (or not) to see differences in performance.  But yes, please do and post!

The facts of octane rating of a particular grade of fuel may or may not be a relevant factor in this equation..
The consensus opinion (okay -the world being flat was also a consensus opinion at one point) for which there is a good deal of testing on and for, is that primarily, a higher octane rating in a fuel provides a benefit to reduce knock (pre-ignition) in typically high compression engines.
The official evidence says that an octane increase alone won't make a difference to an engine that doesn't knock, so it's a waste.
(If your engine STARTS knocking - Go back to super because you NEED it!)

I would point out that most of the testing evidence I've seen addresses power performance.. Tested on a dyno - BUT..
Has anyone seen test results pointed towards comparisons between fuel grades based on fuel economy, or engine performance at the opposite ends of the performance curve (i.e. startup / warmup / redline performance) ?  These are the areas where I noticed a difference.  Not in power output.

At this point, can anyone can say with authority (impassioned opinions aside) exactly what is happening, and what is causing any performance change?
My contention is that I did notice unexpected changes, and think it worthy of further investigation.
Maybe that investigation has already been done.
Maybe any potential benefit may be isolated to specific cases.
Maybe not.
If so, maybe we need to do the testing ourselves...

60
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 30, 2017, 11:29:43 AM »
Interesting, far more interesting and valuable than one or two random members tracking partial data. Mods?
Aye Captain!
By Mods, I'm thinking you meant bike modifications?  Like a 4 into one / velocity stacks / cams ...
I'm thinking logistically, a home on the forum would be good if there is serious interest in pursuing this..
Does anyone know the forum moderators and perhaps have a conversation with him/her/them ?


61
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 30, 2017, 11:20:29 AM »
https://www.afpm.org/State-Motor-Fuels-Specifications/
SG - Wow - Exponential expansion of fuel factors... It looks like most of what they address in statutes (based on a cursory read) are the vapor pressure and required additive(s) and limitation on what a particular state considers a "naughty" ingredient rather than specific input formulation requirements...
But still... Even in the same state at the same time there could be multiple local variants.... 
This could skew results on a ride where the bike gets different formulations even if they are from the same retail name and grade....

62
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 30, 2017, 11:00:46 AM »
MrF - Good post.
I have spreadsheets for everything else ;-) but I never created one for my bike's mileage.
To this point I've had so little variation that it didn't seem necessary, but you gave me an idea.
I'm thinking if other folks want to participate, perhaps some data in a common format would provide grist for the analysis mill...
I was thinking:
Bike make / model / beginning mileage
Combustion intake type (carb or injected)
Run log - miles driven that day / time of day (multiple runs per day)
Environmental Factors - temp/humidity
Ride type (commute/canyon race)
Ride "Quality" Open road / Heavy traffic / etc
Unusual activity - e.g. major throttle application to avoid brain dead cager / outrunning a train (I'm joking)  whoohoo1
... and a summary of:
Total Miles on Tank
Total Gallons added
Brand of Gas and grade
Fuel additive  MTBE / Ethanol
MPG (calculated)
If you can think of any other pertinent factors, great.
I wonder if the moderators might be interested, and if there might be a way to capture the info on the forum.
Would an oil company want to get involved... but (as usual) I'm thinking ahead...

Like you, I am intrigued how an adequate (in terms of octane rating) fuel could be outperformed by a different formulation that theoretically shouldn't be making any difference... From feedback on the forum, the surprise results I had seem to be more prevalent than just a fluke.
With enough data, a design of experiment could be conducted to statistically determine significant factors, but shy of that it is possible that a pattern could emerge... Maybe some brands are better than others.. Maybe fuel injected bikes show no difference.. Maybe the mpg increase "evaporates" over time... Who knows.  At this point it's all conjecture.

In any case, I think the results could be interesting, and it could make for an entertaining forum "class" project.... 

Have a good one!


63
Your Honda Nighthawk / Re: Time to sell....regretflly
« on: August 29, 2017, 12:20:30 PM »
Don't feel bad, cause it's a great ride you had...
 bkr3
As far as young... I recently officially joined the old farts club..
Don't you have to be 65 to get in?
og2
Anyway, the gunfighter is a lot lower, but it's not going to help with the dismounts, but glucosamine does!
Hey, you can feel good about passing along a *nice* machine to someone who can ride it without wincing...

64
Your Honda Nighthawk / Re: Time to sell....regretflly
« on: August 29, 2017, 11:01:36 AM »
One thing that helped me was putting flip up pegs on my case savers - Let's me stretch out on a long ride...
Likely too late to help you...

65
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 29, 2017, 10:41:37 AM »
MrF,
First of all, a very nice and reasoned reply.
I am in agreement that a difference in the octane rating in and of itself is very unlikely to be causing any observed changes, real or imagined.
Although the original thread post mentioned octane, myself and others, were commenting on OBSERVED changes in behavior in our machines, based on a fuel change.  In my case, I never attributed any of these to "octane" or an "octane rating". 
Maybe regular vs super would be a better way to couch it.
While the argument was focused on octane, those ranting about that (IMHO) completely missed the point.

Your test result for octane differences and horsepower were again solely octane based, and jetting changes were required...
It could be that my bike's setup is taking advantage of the new fuel, and the regular it always used wasn't ideal.
I don't know either way about that.

For me, it was a question of the results of using regular unleaded vs. super unleaded, in my case, the Mobil Corp product suite, and observing any differences, either positive or negative, between them to address the controversy initiated by the original poster (Rubo?). 
I had no expectations either way, but I anticipated there would be no difference, largely, because as you stated, the consensus opinion that I was aware of is that using a super grade isn't necessary and/or provides no value, if there is no pre-ignition (knock) using regular fuel.  I know that's "common" knowledge.

But - Gasoline is not "octane" - It is a complex chemical formulation consisting of a large and varied number of initial components, variations in process, and very different additive packages.  To argue, as some have, that there can't be a difference in fuels because more octane won't help, is in a word - stupid, because it ignores a vast number of differences.
Observed results cannot be ignored and dismissed while claiming to have a "scientific" orientation.

My feathers got ruffled when I laid out a reasonable outline of the experiment I conducted, and those results were summarily dismissed, in no small part (IMHO) to an emotional connection to a theory that would not allow for any disagreement. 
This is a classic example of corruption in the scientific method.

There IS more than just my mileage difference as empirical evidence, but speaking of that, if you read back through my posts, I did not expect to discover ANY difference other than the extra money I spent.
But I did.
I did not drive differently. 
I drove the same route under the same conditions in order to do an apple to apple comparison, with less variation than most could accomplish, due to my somewhat unique circumstances.
There was a significant difference in mileage. 
I've NEVER in 11 years got over 50 mpg and I measure mpg on every tank.
If it was you making the comment on data points, I agree with you, or whomever made that comment, that more is better and necessary to confirm.
The point for me was that it was worth exploring, because there were unexpected results, rather than trying to explain it away because it didn't fit a  theory.
There are other cases of evidence:
To wit - After the switch to super, idle speed increase was observed by at least 3 people, myself included.
Conversely, I think it was Captain Kirk, who noted he had to turn up his idle to prevent stalling after switching back to regular. 
Regardless of anyone's position on octane, the fact remains that an observed, quantifiable and measurable difference occurred. 
You cannot make an argument (if you wish to be taken seriously) that this is a result of bias on the part of the observer.

Again, I think it was the Captain who noted, as I did, that his bike was able to run without a choke much sooner than when using regular.
This is an easily observed phenomena, just like the idle. 
My bike didn't stop stumbling because I wanted it to because I wanted super to be better, and for someone to summarily dismiss that observation as bias is to me, offensive. 
I happen to be a retired, certified Six Sigma Master Black Belt, and I've saved millions of dollars via implementation of process improvements.
I think I can manage a simple comparison mpg test without screwing it up.

As far as subjective factors, e.g. more power - I didn't notice that, nor is it something I care about. 
My bike has plenty of power for me, but the other item mentioned, "runs better", although subjective does have a basis for me, as I mentioned that my bike's consistent stumble at the top end of my tach went away... "probably" not because I wanted it to because I tried a new fuel.

The bottom line for me is, there appear to be several benefits to the use of Mobil premium fuel in my bike vs their regular.
I intend to continue (as I always have) to monitor and calculate my mpg and I would encourage others to experiment on their own and report their results, and while doing so, I would suggest that folks be aware of the potential for bias, which can impact results, but not typically tachometers.
 haphap

That being said, I stand by my comment - While I am not a chemical engineer, nor claim to be, and have no specific theory as to what factor or factors are at work between the two fuel grades I've tried which caused the observed improvements, IMPROVEMENTS WERE OBSERVED, and to dismiss those noted as a placebo effect or observer bias has no basis in fact.


66
Your Honda Nighthawk / Re: My '96 CB750 "Dragon Bike"
« on: August 28, 2017, 08:52:32 AM »
Thanks DD, I have the Junior, and have it hooked up to my Hawk.  I had a prior co worker that had a WOLO air horn on his VTX. That think was loud. I drive a  semi, and would love to have something as loud as my semi horn.
I've heard those WOLOs are good..
I had bought something similar, but could't find an easy place to mount it (before my fairing) so I went with the fork reflector mounts.
It seemed an interesting coincidence that the horns and reflectors used the same size thread.... anyway...
With any decent horn you'll need to add a relay because there isn't enough power.
It's pretty simple wiring..
One other thing I did was to add a cigarette lighter type plug when I put in the horn relay so I have a 12 volt power source without having to turn on the ignition.  It works great for phone charging and stuff-like-that-there... haphap

Have a good one, Gordon!

67
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 28, 2017, 08:34:03 AM »
Since you guys put it that way... og2
Since switching back to 87, I've had to adjust the idle speed up, and it bogs the first mile or so running through the gears until temps start to come up.
So, I'm not questioning the science, but rather, stating there is more to the issue than meets the eye. Could it be ethanol or additives? Quite possibly. But there is a difference.
Aye Captain !
Your experience and mine are the same regarding warm up, which prompted my mention of a very noticeable change.
My idle on super is also a bit (~150) higher, but I like it that way.   
The increase in idle speed  seems to be a consistent observation, as also mentioned by the original poster.

From what I recall, science "IS QUESTIONING".. why something is, a theory as to causation, and experiment / observation for confirmation.
In this case the "science" would be an observed change (in fuel) a theory as to causation (additives?) and an experiment to confirm it.

What science isn't, is the dismissal of observation that does not fit a desired theory, but sadly, scientists are some of the worst offenders in this regard.

For myself, the bike's change in behavior is worth 20 cents a gallon on a vehicle getting 50 mpg...
I'm happy with a change that lets my bike run leaner sooner (less time on choke) and 10% mpg improvement.

I will continue to monitor mpg performance (it's always a good idea - a change for the worse is a great head's up) and post my ongoing results, but I think a new thread would be a better place.  With enough contributors, it might be possible to discover what formulations and their additives seem to be making the difference... Maybe not, but at least it might provide an interesting discussion topic and give people a reason to ... ride...
 ridn2

Back to the original point of this post... trying to make the case that using super results solely in a placebo effect on the rider is ridiculous, IMHO.
 

68
Your Honda Nighthawk / Re: My '96 CB750 "Dragon Bike"
« on: August 27, 2017, 07:02:12 PM »
Good Stuff Gordon...
Mounting aside, do yourself the favor of a decent horn so you can be HEARD over the MP3 in the car changing into your lane.
If it sounds like an 18 wheeler, chances are the driver will react. (Personal experience)
For your battery...
Pick up a "Battery Tender" or junior version of it.
They include a harness and quick hookup so you can keep the battery fully charged.
AGM's like to be kept full and if so, pretty well last forever.
Mine is now 10 years old and still has new specs on a tester.
This is especially true (charging) if you don't ride your bike for extended periods.
Regards...

69
Your Honda Nighthawk / Re: Time to sell....regretflly
« on: August 27, 2017, 06:50:34 PM »
Wow - Nice bike at a great price!
I doubt you'll have a problem selling the bike if it runs as good as it looks.
If I wasn't already in love with my '96, I'd fly there and buy it...

You could mention in your ad that the bike has experienced a "total eclipse"...
Sorry... I'm still jealous I didn't get to see it!

If you don't sell it right away, have you tried or considered alternative seating?
I replaced my stock seat with a Corbin gunfighter, and a gel pad, and my hips are happier!
In any case, good luck...
P.S. There are many others who have lost their 'Hawks, so you can still 'hang around' 
:jkam:
Regards



70
Don't know if anyone has ever linked this before, but it was a great and funny read. 
http://www.robertbrockway.net/2016/10/13/the-2003-honda-nighthawk-750-is-the-greatest-motorcycle-ever-made-and-yes-i-will-fight-you-about-it/
Ht Dog -
Three letter synopsis...
O M G !
or
BBE
(Best Blog EVER !)
Too funny - Thanks!

71
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 27, 2017, 05:25:00 PM »
Pants - I think you're the one grinding the wrong ax here..
YOU seem to be the one with a vested interest in an outcome - Not me.
It apparently offends your sensibilities that you might have been wrong all along...
Sorry you were attacked by that gas station attendant who tried to get you hooked on super.
 
I would like you to explain in your extreme wisdom, how the fuel change described by the post originator resulted in an increase in RPM's enough that he needed to adjust his idle speed. 
Was his intense love of super causing the bike to rev up?

As for the choke, my bike has always been cold blooded..
It's air cooled, so not a major surprise.   
I have always needed to let it run with the choke on for 3 or 4 minutes, and with a small amount of choke when first underway or the engine will bog out. 
It has acted the same way for YEARS and not significantly different regardless of weather, but then I drive when the weather is "nice".

For the week of regular vs super choke comparison, the weather was the same all week and I left at about the same time.
With super, I get no stumble, and I need no choke by the time I'm at the end of my driveway.  This has been consistent.
While it was a freekin' obvious difference to me, I did not expect it, and it was NOT MY FEELINGS attributed to premium fuel.

As far as the mpg test, I drove the same route at the same speed with the same stops and compared mpg results, and they were statistically different.
I did not expect a different result, and I didn't change what I did to bias the test.
The next time I've got a set of local only days I plan on doing it again, as while I always calculate my mpg, I don't have a baseline for the interstate, nor can I create one, because there are too many other variables.

I got into this as an experiment, with absolutely NO predisposition that a fuel change would make any difference... But it did.
I find your contention of bias personally offensive and completely unfounded.

I'm not trying to change your mind - I really don't care what your opinion is.
As far as anything beyond monitoring my mpgs, I am not inclined to go through extreme measures so your panties are no longer in a bunch.

For anyone else out there, give it a try. 
See if it makes a difference. 
Maybe it will, for worse or better..
Maybe you won't notice a thing... but..
Either way you could contribute your OBSERVATIONS rather than blathering your Theory.



72
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 27, 2017, 11:58:18 AM »
Hi guys
Lately I switched to 92 octane and my bikes 91NH runs smoother faster and seems to have more power.Noticed idle increased significantly and I adjusted back down but was puzzled why switching the octane increased the idle speed.
Anyway am I experiencing placebo effect or actually my bike runs better.I know it does but need your guys opinions
Suddenly it all makes sense...
It may not be the octane, but other formulation factors that seem to agree with your (and my) bike.
I noticed an unexpected mpg bump (which I will be reconfirming) and in your case, if the same metered fuel results in increased rpm (your idle), it is using less fuel for the same output, which would seem to provide some collaboration for my controlled experiment resulting in improved mpg...

I didn't really notice a change in power output, but one of the most dramatic changes I noticed was that the bike became considerably less "cold blooded"..  My time required on choke was reduced ~ 50%..  Did you notice a similar effect?

73
Your Honda Nighthawk / Re: My '96 CB750 "Dragon Bike"
« on: August 27, 2017, 11:31:49 AM »
That's a beautiful bike DD.  You've given me some ideas for mine!
Were I Elvis... I'd say...  "Thank You! .. Thank You Very Much!"
haphap
Glad you liked the pics...
I'm glad you got some take aways..
You can always make a good bike better!
I just saw your red bike - Looks really clean.
A big safety improvement at relatively low cost is a replacement of the beep beep horn..
On your CB 750 the front fork reflectors make an ideal horn mount location... It's like it was designed for it.
Hacksaw off the screw on the back of the reflector and glue it back on the horn...
I used the beep beep spot for mounting a horn relay.
Anyway, thanks for the compliment!
DD

74
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 27, 2017, 09:56:55 AM »
Pants Man -
Saw your post after mine, but it looks like I proactively addressed them.
As a former Six Sigma Master Black Belt, I take data seriously and I know about variation in process and measurement.
Never said octane made the difference.
Never said it produced more power, I don't think it does.
You are hung up on octane, I'm not.
You are quoting and attempting to establish theory - I'm not - Just reporting observations.
But I can say this - There were multiple positive results that were not subjective, and measurable.
Because you can't explain them, doesn't mean I was hallucinating.
Like Yogi Bearra said, "In Theory, Theory and Practice are the same... In Practice, they ain't"
 haphap

75
General Motorcycle Discussion / Re: Placebo or Real? 87 or 92 octane
« on: August 27, 2017, 09:36:47 AM »
Okay...
Confirmation bias - When you "hope for and/or expect" a different result... Very familiar with the concept.

I did not expect a different result and conducted the experiment fully "expecting" that there would be no difference at all.
You guys may not "buy" subjective assessments, but again I wasn't hoping for better performance, I just noticed it.

Particularly when around 8 grand going towards redline, the bike would stumble a bit, has been doing it for years and ceased doing it on super. 
Same run, same bike, same rider... only difference being fuel... 
I'm not sure that qualifies as subjective.   
Surprise maybe, but subjective?

As far as warm up, I've been living with the bike for 11 years now, and I noticed a significant difference in time required on choke (~ 50%)
That is not subjective, it is a measurable quantity - time. 

While there could be a difference in tank fill, it has never affected my results before. 
I calculate MPG on every tank, and fill it at the same station, to the same level. 
For the local travel that I do, it's within 1 mpg variance, which is why I decided to do the experiment in the first place.

I never said that the difference in octane made the difference in mileage and performance, and I still would not say that - Other posters did.
Gasoline is an incredibly complex chemical formulation, and there are different additive packages by grade.
Apparently my bike *really* likes Mobil Premium...  How many folks out there can get 50 miles per gallon on a CB 750 ?
Probably not many - But again, I never stated that "you" would see a difference - I just reported that I did.

I'm not sure, but doubt that there would be a difference measurable in horsepower on a dyno.
There are many aspects of engine performance beyond the power produced, especially if some factor in the fuel is improving mileage..
Same power using less fuel does not mean that the engine produces more power at a given rpm, just that it is more efficient...
One thing I did NOT notice, was any difference is horsepower - just the improved mileage, less warm up and lack of stumble close to redline.

Mr F makes a great point that I agree with - the more data points the better.
Unfortunately, I can only do "the experiment" when I'm traveling the same route, or a whole host of other sources of variation can creep in, so it will be a couple of weeks before I can do that again, but I'll post those when I can, accurately, and without "confirmation bias".

That's the best I can do, since I don't have a dyno available; I think the logistics of evacuating one fuel before using another is more trouble than I plan on giving myself; and I doubt there would be any measurable difference anyway.

Whew...



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