new bike and starting issues

[asthlan1]

i just got a 1984 NH 650, long story short I got a new battery cleaned the carbs(im a noob so best i could)
the bike will start but pipes 2 and 3 stay cold and at idle it sounds like knocking im guessing/hoping cause the two cylinders arent firing if i give it gas
the knocking goes away
at this point i bought two coils and have tried both, all new plugs gapped corrrectly

tested the plugs all are producing spark
 
back to the carbs? looking for advice

[ExTex]

The 1st step is to make sure there is gas going to the carbs of the dead cylinders.
Get an 18 inch piece of clear Tygon tubing the correct size to slip over the drain nipples on the float bowls.
Place the cycle on it's center stand.
Turn ON the petcock and apply vacuum to the petcock to insure gas fills the float bowls.  Use mouth or syringe to create vacuum.
Attach the Tygon tubing to one of the carb's bowl nipple.
While holding the open end of the tubing vertical, use a screwdriver to open the drain at the bottom of that barb float bowl.
Check the height of the gas in the line.  It should be about the height of the float bowl seal.
Repeat for other 3 carbs.  The heights should be about the same.

You can do the same test by using a clear small jar/bottle to measure the amount of gas drained from the floatbowls,
but the 1st drain will include gas in the supply hose.  In this test you can also look for trash in the float bowls.

After this test, you may have found a problem.  If not,let us know.

Ride Safely,

[fortyhourdays]

Let me start by saying    

I wouldn't worry about the knocking sound.  It's most likely because of the cylinders not firing.  When you pulled the plugs on 2 and 3 to check for spark, are they wet with fuel?  Also, when you cleaned your carbs did you disassemble them completely, or leave all 4 of them connected as a bank.  I ask this because if you separated them, then they would most likely need to be re-synced.  Even if you didn't split the bank up, I would still want to check and make sure they are synced properly.  Did you do a bench sync before reinstalling them?  Have you cracked the float bowl drain screw on the bottom of carbs 2 and 3 to see if there is fuel in the float bowls?  When you give it gas you say the knocking goes away.  Once it's rev'ed up like this do the other two cylinders start firing?  Sorry for all the questions, but the more details we have, the more help we can give.

[asthlan1]

ok @ Extex
I drained the bowls all four has the same amount everything looked normal
@40hrdays
I just pulled all four plugs again 1 and 4 are black 2 and 3 are clean as a whistle. just so you know i have the air filter out right now as it is disgusting
when i cleaned the carbs i left them as a bank and did the pinesol overnighter,im new to this. did not bench sync, I tore everything else appart that i could but i did leave them as a bank, the carbs looked synced tho they all open evenly when i open them
as for the knocking, when its idling it sounds like knocking but when i give it gas it the knocking goes away , but the pipes stay cold (2 and 3) so im assum ing they still arent firing when i give it gas. How could i tell besides pipe heat? i appreciate everyones help

[fortyhourdays]

So are you saying that the 2 and 3 spark plugs are not wet from fuel at all after starting it even though they are not firing?  Are you saying you're running it without the air filter?  This could be the issue since running without an air filter would cause a very lean running condition.  I'd get a new air filter as the first order of business. 

[asthlan1]

 the filter being out might be causing the black plugs in 1 and 4 but i dont understand why 2 and 3 are clean still, Im guessing they arent firing I am in the process of geting a filter tho i know it is important. Im gonna check the gap again

[asthlan1]

pulled plugs after trying too start they are wet (2 and 3)

[asthlan1]

pulled carbs again and cleaned every crack and sprayed carb cleaner thru everyhole still onlly running on two cyclinders, i bought a compression tester how do i use it? do you think it could be compression issue?

[NightHawked]

Pull a spark plug, replace with compression tester, crank engine and read gauge. Repeat for four cylinders, releasing air if necessary.
Possible but don't know how probable.

I take it you have spark and gas at each cylinder?

[ExTex]

I think you pull all four plugs at once before you start testing

Here is a good procedure.
http://www.dansmc.com/compression_test.htm

This is a good test if your engine won't start.

Ride  safely,

[asthlan1]

i got a compression tester but apparently it doesn have the right connection, does anyone know where to get the right connector, i tried to hold it over the spark holes but sometimes i could get a reading and other times it just blew the comp tester  off the hole, on a side note the vacuum hose that runs from the intake to the petcock isnt sucking it is blowing out and keeps blowing the hose off the petcock of course it is on the number 2 cylinder so i was wondering if that meant anything other than number 2 isnt firing?

[asthlan1]

I was able to fire up 1 and 4  with the other(right) coil,so both coils are working, my question now is can i try to fire 2 and 3 with the left coils wires(from cdi not plug)? this would narrrow it down to the cdi box only putting out good spark to the left coil and not the right.

[wiskey]

Have you checked you ignition? on my 750 it was points, swapped in an electric ignition and BINGO!

[asthlan1]

blew the starter solenoid i think, just clicks once when i go to start  it, battery is brand new sealed gel , ordered a starter solenoid and a cdi box parts should be here monday or tuesday. once i nstall everything i will try to fire it up again see if the other two cylinders fire with the new cdi

[wiskey]

hardest part of building these bikes is waiting for parts!

[asthlan1]

your telling me, part of me wants to just order all the parts people normally have trouble with now so i dont have to wait a week each time something breaks, but then i dont and then it breaks and then i wait 5 days for a part rinse lather and repeat...

[ExTex]

I hope the new parts solve the problem, but if they don't.  Consider the pulse generators.
You Nighthawk has 2 of them, one for each coil.  Having 1 coil not fire sounds like a possibility.
You can measure their resistance to determine if they are bad.  It may be a broken wire or a bad connection.
Something to check while you wait for parts.
It looks like you can buy a new pair for $55 at HB Honda.
Item #04 GENERATOR, PULSE, 30310-ME5-000   Retail: $80.18 HB Honda: $55.13
 http://www.hbhonda.com/fiche_section_detail.asp?section=123868&category=MOTORCYCLES&make=HONDA&year=1984&fveh=2959

Have a good spring.

[asthlan1]

Thanks for the advice, got the parts in and the same issue, just a click when i try to start. so i took the starter off and opened it up. is it bad when black soot and copper wires fall out? anyway im gonna rebuild it and while im at it im gonna replace the pulse gen also. I really like the bike so im not gonna half a$$ it.  so while i once again wait for parts im gonna work on the brakes. 

[ExTex]

It is fine to replace parts, but a little work may save time and money.
Get a Honda service manual and a digital multimeter (DMM).
Sears sells a good meter for $20 ($15 on sale usually).
Even a Clymers manual will be of help.  Manuals cost about $40.

For example, I would not buy new pulse generator parts if the old ones met secifications (all you need is an ohm scale on the DMM.

Good luck with your bike.

Ride safely,

[Brittles]

+1

[asthlan1]

I got the mulitmeter and ordered a manual...

[asthlan1]

UPDATE . so the new(used) cdi box and the starter rebuild have solved the 2 and 3 cylinder issue, so now all four are running, problem now is it wont idle and it wont start everytime,
also i dont know if this matters but when i try to start it and it wont start , when it is done cranking there is a pssssssssh sound coming from the im guessing the airbox. when its running it sounds good tho..... also when running i had the choke all the way open.... 

[ExTex]

One of your exhaust valve lifters may be not working. 
Thus pressure from the cylinder leaking back into the air box.


happed to me once, but it self healed.

Ride Safely,

[asthlan1]

another update i think my idle is not set right, the manual should be here anyday now, but my bike it trying to idle at 400-500 rpm. if i hold it at 800-1000 with the throttle it purrs just fine. throttle is also very responsive, i feel im getting close

[Bumblebee]

Low idle is generally 1000 +-50 RPM.
500rpm is way too low.