Clutch disengaging? or maybe it's not...

[nashvegasmatt]

Let me start by prefacing this a bit. I purchased an 82 cb650sc from a friend for $300 who needed the money. The bike ran a few months back, but has been sitting outside. He saw it run sitting still but never drove it, so it could be something simple. My problem started this morning when I went to start tearing it down for the first time. Before I started, I said what the heck, and tried to start it. With the switch to run, the key engaged, and it in neutral. The starter just spins. I know the starter clutch is bad, because upon tear down, the gear that the starter connects to spins both ways fairly freely. Unless I am wrong that is the #1 indicator that the SC has failed. I'm thinking of buying a new one, because I can't find any sort of rebuild kit for it. anyway......back to the original problem. ...... I accidentally bumped it in to gear (with the rear wheel up), while trying to start it and the starter attempted to engage even though the clutch lever wasn't being pulled. This is kind of a concern for me. It should not try to start in gear without the clutch lever being pulled right? Is there a clutch relay or something that could be stuck in the on position for the clutch. The cable doesn't seem to be the problem, nor does the internal components of the clutch itself, release mechanism, or ball bearing push. Anyone have any ideas? I'm fairly new to bike mechanics, but have dealt with plenty of cars, so go easy on this noob...

[TDodge7]

The switch for the clutch cut off is usually on the controls next to the clutch lever , but it's not really a problem , you have a neutral light so you can tell when it's out of gear . It's certainly nothing bad (and not all bikes have a clutch safety switch so it may actually be normal for your 82 ), probably just a sticky switch or a previous owner that disabled it , I sometimes disable them myself , especially when I'm tuning and I have to keep starting and stopping the engine.

[nashvegasmatt]

The switch for the clutch cut off is usually on the controls next to the clutch lever , but it's not really a problem , you have a neutral light so you can tell when it's out of gear . It's certainly nothing bad (and not all bikes have a clutch safety switch so it may actually be normal for your 82 ), probably just a sticky switch or a previous owner that disabled it , I sometimes disable them myself , especially when I'm tuning and I have to keep starting and stopping the engine.

the reason im concerned is that if I had both wheels on the ground in first gear and hit the starter button thinking it was in neutral.... wouldn't the bike lurch forward in an attempt to start?

[Bumblebee]

and not all bikes have a clutch safety switch so it may actually be normal for your 82

Maybe however not on this model series.

Switch at the clutch lever has been bypassed most likely.

And, um, get a shop manual and torque wrench. Since you're deep enough in to replace the starter clutch, you're deep enough in to do some serious damage by not having things assembled and/or torqued correctly. (You do not want to see what happens if, say, a clutch nut comes loose at 6000 RPM because it was pulled-tight-until-it-felt-right)

[nashvegasmatt]

and not all bikes have a clutch safety switch so it may actually be normal for your 82

Maybe however not on this model series.

Switch at the clutch lever has been bypassed most likely.

And, um, get a shop manual and torque wrench. Since you're deep enough in to replace the starter clutch, you're deep enough in to do some serious damage by not having things assembled and/or torqued correctly. (You do not want to see what happens if, say, a clutch nut comes loose at 6000 RPM because it was pulled-tight-until-it-felt-right)

you do agree though that I might as well do the starter clutch? is there such a thing as a rebuild kit? springs, rollers? I guess I'm trying to avoid purchasing a brand new core if it's only those few things.

[mattrowe19]

I wouldn't be too concerned about it. My 82 450 turns over and starts without the clutch pulled in as well. However, it's a VERY habit to pull the lever in while starting. The neutral light isn't fool proof and pulling the lever in ensures that the bike won't go anywhere when you start it.

[Bumblebee]

you do agree though that I might as well do the starter clutch? is there such a thing as a rebuild kit? springs, rollers? I guess I'm trying to avoid purchasing a brand new core if it's only those few things.

If the starter clutch isn't working properly, you have to do something with it.
Any parts that are out of tolerance or showing wear need to be replaced. Look up the parts online and see what is available.
Don't get all wrapped up in the idea of prepackaged rebuild kits. Sometimes the individual parts are cheaper than the kits and in this case, there's not a lot of parts involved to start with. Besides, this is a low failure part that probably doesn't have a kit.

Don't go cheap on yourself though. This is an internal part that is a big hassle to get to. $20 now might sound nice however not if you have to open the case up again two years from now and replace the more spendy part you tried to avoid replacing in the first place. Do it right once and it won't have to be worked on again for another 30 years.

[nashvegasmatt]

I wouldn't be too concerned about it. My 82 450 turns over and starts without the clutch pulled in as well. However, it's a VERY habit to pull the lever in while starting. The neutral light isn't fool proof and pulling the lever in ensures that the bike won't go anywhere when you start it.

im not sure my clutch is working correctly and that is why I'm asking about sensors and whatnot.

[nashvegasmatt]

you do agree though that I might as well do the starter clutch? is there such a thing as a rebuild kit? springs, rollers? I guess I'm trying to avoid purchasing a brand new core if it's only those few things.

If the starter clutch isn't working properly, you have to do something with it.
Any parts that are out of tolerance or showing wear need to be replaced. Look up the parts online and see what is available.
Don't get all wrapped up in the idea of prepackaged rebuild kits. Sometimes the individual parts are cheaper than the kits and in this case, there's not a lot of parts involved to start with. Besides, this is a low failure part that probably doesn't have a kit.

Don't go cheap on yourself though. This is an internal part that is a big hassle to get to. $20 now might sound nice however not if you have to open the case up again two years from now and replace the more spendy part you tried to avoid replacing in the first place. Do it right once and it won't have to be worked on again for another 30 years.

Being a noob to the CB650's, should I just buy new parts from Honda, or should I look online somewhere else. Also, sites like bike bandit and such, show you the schematics, but do not tell you how many springs or rollers one might need. I'm up for buying all new parts, but if I buy a SC from honda for $140, thats just the part, minus the springs and rollers right? Not to mention the fact that I do not have a garage, so I have to disassemble replace and re-assemble in one day. I can't leave it in pieces while I figure it out.

[hppants]

Surely I am missing something, but how can he deduce a bad starter clutch from the information we have been given?  Does that model have a starter chain?

[Bumblebee]

im not sure my clutch is working correctly and that is why I'm asking about sensors and whatnot.

Hold on a minute. This is starting to get confusing.

1. The starter clutch is apparently bad.
2. It will start while in gear without touching the clutch lever.
3. Based on #1 and #2 above, the starter clutch has failed yet you can push the start button while it's in gear and it tried to start the engine anyway. You stated that it "attempted to engage." Can we assume that this means that only the starter turned and not the engine itself and the starter did not try to power the rear wheel? That was implied yet not made clear. Spinning the starter is one thing. Engaging the engine is a different system.
Now:
4. The clutch may not be working right. The clutch is not directly related to the starting system. Or are you talking about the starter clutch vs the engine/transmission clutch mounted on the ride side of the engine case?

I'm getting the impression that things are not being thought through properly or at least not communicated clearly.


HP: No starter chain. The starter goes into the upper transmission case and meshes with a starter idler gear. The idler gear connects to a gear that is attached to the starter clutch that is mounted on the transmissions primary driven shaft.



And Nash, a little reality check here. Replacing the starter clutch requires you to do this: Access the top end of the engine by pulling the seat and tank which you probably already have done. Then pulling the carburetors (just getting carburetors off the hardened intake manifold boots for the first time often takes an hour or two for most people), disconnecting all the electric connections to the engine, removing the drive chain by sliding the rear wheel forward, pull the heads and cylinders, remove the engine case from the frame, split the case, inspect everything, replace parts as required, inspect and clean absolutely everything. Then reverse the disassembly process including installing all new seals and gaskets as you go along plus setting the engine timing when you get to the heads.
This is not a one day project. I know this motorcycle quite well (650standard which is almost identical to the 650SC at the engine level) and have a lot of wrenching experience. To do it properly, I am looking at 3+ days of work if I already have all the parts in hand. You will likely have the engine disassembled for a week.
Take a look at our resident Dining Room Mechanic, aka fortyhourdays thread where he's having to do a full teardown. Excluding his piston related damage, THAT is what you're facing.

[nashvegasmatt]

im not sure my clutch is working correctly and that is why I'm asking about sensors and whatnot.

Hold on a minute. This is starting to get confusing.

1. The starter clutch is apparently bad.
2. It will start while in gear without touching the clutch lever.
3. Based on #1 and #2 above, the starter clutch has failed yet you can push the start button while it's in gear and it tried to start the engine anyway. You stated that it "attempted to engage." Can we assume that this means that only the starter turned and not the engine itself and the starter did not try to power the rear wheel? That was implied yet not made clear. Spinning the starter is one thing. Engaging the engine is a different system.
Now:
4. The clutch may not be working right. The clutch is not directly related to the starting system. Or are you talking about the starter clutch vs the engine/transmission clutch mounted on the ride side of the engine case?

I'm getting the impression that things are not being thought through properly or at least not communicated clearly.


HP: No starter chain. The starter goes into the upper transmission case and meshes with a starter idler gear. The idler gear connects to a gear that is attached to the starter clutch that is mounted on the transmissions primary driven shaft.



And Nash, a little reality check here. Replacing the starter clutch requires you to do this: Access the top end of the engine by pulling the seat and tank which you probably already have done. Then pulling the carburetors (just getting carburetors off the hardened intake manifold boots for the first time often takes an hour or two for most people), disconnecting all the electric connections to the engine, removing the drive chain by sliding the rear wheel forward, pull the heads and cylinders, remove the engine case from the frame, split the case, inspect everything, replace parts as required, inspect and clean absolutely everything. Then reverse the disassembly process including installing all new seals and gaskets as you go along plus setting the engine timing when you get to the heads.
This is not a one day project. I know this motorcycle quite well (650standard which is almost identical to the 650SC at the engine level) and have a lot of wrenching experience. To do it properly, I am looking at 3+ days of work if I already have all the parts in hand. You will likely have the engine disassembled for a week.
Take a look at our resident Dining Room Mechanic, aka fortyhourdays thread where he's having to do a full teardown. Excluding his piston related damage, THAT is what you're facing.

Exactly... only the starter is turning not the motor itself.

Ok, well I've read several threads where people have changed the starter clutch by dropping the oil pan, removing the clutch and going in through that route for replacing it, and therefore not needing to split the case. I've read quite a few. Maybe I was reading it on a different year bike, but that wouldn't work is what your telling me? I'm feeling less enthusiastic about my $300 dollar purchase as the day goes on. I don't have a garage and live in an apartment, so pulling the motor here is not an option.... I just feel like there is something I'm missing, because it started up 2 months ago fine, and now it won't budge. I'm gonna have to think this over. If you guys have any suggestions please let me know.

[nashvegasmatt]

alright... after tinkering a bit more with a full battery this time, I have come to some conclusions.
1. Something in the motor is clanking around when trying to start....(you can hear in the video)
2. When it is in gear or in neutral, the bike will try to start no matter if the clutch is pulled in or not.
3. Most of the electronics seem to be functioning properly according to my volt meter.

I read elsewhere that if the starter clutch gear turns both directions it is bad, then I read somewhere else that it is supposed to turn both ways, just more difficult backwards.... any insight here?

Next question. Could this be the alternator/starter chain? Could it be broken? How would I know without pulling the motor?

Finally the clutch issue... Since the bike tries to start while in gear, I feel like maybe I should start here. How is this possible? am I maybe in a false neutral? Nothing on the wiring side seems to be out of place...I followed the clutch cable down to the clutch itself and nothing seems to be out of line...

I guess I'm at a weird place here. I have very little invested in the whole project, and am not able to split the case at my apartment for obvious reasons. Should I just sell and run away? I am not wanting to sell, but if splitting the case is the only option, I do not see how I have much of a choice.

HERE'S THE STARTING VIDEO

"http://img163.imageshack.us/flvplayer.swf?f=Mq4o"

[NightHawked]

It doesn't sound healthy does it. I can't help with WTFII. Another member, fortyhourdays, has tore down his motor in his apartment. Food for thought. You could also do a motor swap, if it turns out to be real bad. You don't have that much invested so the $300. I've heard for a motor might be doable. Also if you don't have alot in it you don't have to get alot out of it to break even. Goodluck whichever way it goes.

[nashvegasmatt]

It doesn't sound healthy does it. I can't help with WTFII. Another member, fortyhourdays, has tore down his motor in his apartment. Food for thought. You could also do a motor swap, if it turns out to be real bad. You don't have that much invested so the $300. I've heard for a motor might be doable. Also if you don't have alot in it you don't have to get alot out of it to break even. Goodluck whichever way it goes.

thanks... If I was a single guy, believe me, the motor would be out and sitting on the dining room floor, but the wife does not go with that theory. so... ya. I don't think this is too serious, because it was running, purchased, sold to me and now it doesn't run.... somethings not adding up. The guy who sold it to me was a friend so I know he didn't ride it or mess with it.

[nashvegasmatt]

question.... upon disassembly of the clutch cover, does the clutch lifter just dangle in there.... that seems kinda weird.

[fortyhourdays]

To me it sounds like the starter is turning your engine over but that the starter idler gear is slipping and grinding every few teeth or something similar to this.  I'm not an expert on this engine though since my rebuild is an 83-85 engine with a starter chain.  It sounds like rebuilding is not an option for you unless you have a friend with a garage who doesn't mind you using it for a month.  If you could find a place to rebuild, I live about 30 minutes from you and could help you along in the process.  Sorry, my dining room has no more space for another bike.

[Bumblebee]

79-82 CB650 all models. No starter chain.

[geemann]

...
2. When it is in gear or in neutral, the bike will try to start no matter if the clutch is pulled in or not.
...

see answer:

The switch for the clutch cut off is usually on the controls next to the clutch lever , but it's not really a problem , you have a neutral light so you can tell when it's out of gear . It's certainly nothing bad (and not all bikes have a clutch safety switch so it may actually be normal for your 82 ), probably just a sticky switch or a previous owner that disabled it , I sometimes disable them myself , especially when I'm tuning and I have to keep starting and stopping the engine.

engine swap or cracking it open, you will need a place to do work.
options:
- a buddy's garage/basement
- your dining or living room
- rented storage place
- rented garage

i have a buddy that did an engine rebuild on an old kawa kz in his dorm room over the winter holiday. so take your pick and get creative!

in terms of further diagnostics without opening, i think you have reached a standstill.  if you are hearing "something in the motor is clanking around when trying to start" then it is def time to split it open. there is no real fast and easy way to do this.  but you are at a spot where we can not really help you until you decide what you want to do.

when/if you decide to open it up, we will be here to offer/provide as much help as you can ask for*.

cheers,
-g


*that is totally dependent on how well you pay us in pics! haha!

[nashvegasmatt]

well In the car forum world, I'm a pic whore.... I myself love DIY tutorials from members...

Idler gear? I hadn't thought about that Jon. Is this replaceable by removing the primary shaft, or are we still talking about splitting the case...(if you hadn't noticed, I'm trying to avoid this...lol) I know it might have any other option.

The one thing I'm still concerned about is the fact that the clutch seems stuck....Like it's not disengaging when I pull the lever in gear.. Are there any places on the clutch I should check for stickage? I know this doesn't resolve the starting issue, but it might help me narrow it down.

[fortyhourdays]

I don't know about the SOHC engine since apparently it does not have a starter chain, but I don't think there is any way to fix it other than splitting the cases.  I'd trust Bumblebee on this one since he's been through this engine before and knows what he's talking about. 

As to your question about the clutch not disengaging, it sounds like it probably needs to be bled. 

[nashvegasmatt]

I don't know about the SOHC engine since apparently it does not have a starter chain, but I don't think there is any way to fix it other than splitting the cases.  I'd trust Bumblebee on this one since he's been through this engine before and knows what he's talking about. 

As to your question about the clutch not disengaging, it sounds like it probably needs to be bled. 

funny that you mention it needing to bled. I was adjusting the throttle cable, when I noticed that the master cylinder is totally empty... I'm sure that's not helping anything, and it probably could go for a rebuild kit. These bikes take DOT 4 right, not DOT 3? What's the difference anyway?

[fortyhourdays]

My manual for 83-85 650 says DOT 3 only.  I don't know if it's the same for your bike but I would think so.  Check your manual to make sure.  I don't know the difference between DOT 3 and DOT 4, but I know DOT 5 is silicone based and should not be used on these bikes according to the manual. 

[nashvegasmatt]

My manual for 83-85 650 says DOT 3 only.  I don't know if it's the same for your bike but I would think so.  Check your manual to make sure.  I don't know the difference between DOT 3 and DOT 4, but I know DOT 5 is silicone based and should not be used on these bikes according to the manual. 

interesting... thanks.

[Bumblebee]

Not possible to bleed the clutch hydraulic line. It's a steel cable.

If it's hard to pull or not functioning properly, adjust the grip or lower cable adjustments. If it's still out of whack, the next step is to adjust the adjustment nut inside the clutch housing, follow the book procedure exactly, no adlibbing allowed or you'll end up doing it all over again.