Clutch not Engaging/Disengaging???

[JBryan91]

Hello all new to the forum here. Recently acquired a 95 vmax from a guy locally here in Texas. The bike sat for bout a year. I had the carbs rebuilt and put them on the other day with no issues. The bike runs great. While checking the controls the clutch lever had no positive feedback and went straight to the handlebar when pulled. The reservoir still had a little fluid in it. Cleaned the reservoir and bled the system normally and reversed bled as well. Even bled the air from the banjo bolt by the clutch master. The clutch lever has great stiff feel and operates normally now. The issue I have is that when I pull the clutch lever in and put the bike in gear it jumps forward and kills itself without me ever releasing the clutch lever.

Any Ideas??

P. S. I did use the search function first and could not find an answer to my issue. Majority of it was "proper" bleeding procedures and full clutch rebuilds/mods.

TIA!!

 

[maleko89]

Wondering if ignition is being cutoff. Is your sidestand up? What happens when you try to start the bike with clutch pulled, sidestand up, bike in gear? It should start. If not, could be sidestand switch, starting circuit cutoff relay, diode assembly or clutch lever switch.

 

[JBryan91]

Clutch lever switch is wired together from previous owner….don’t tell me that’s the issue…..

ignition does not cut. The bike dies because it jumps "in gear" from a stand still and i'm not giving it throttle. Basically its ignoring that i have the clutch pulled in. Otherwise it shifts through the gears normally and goes into neutral fine.

 

[maleko89]

Maybe he did that to bypass the clutch switch, thinking that's the problem. Put bike in 2nd gear and roll with clutch pulled in. When you release the clutch you should feel clutch engage. If so, clutch is good at least.

Otherwise, test that starting circuit cutoff relay or try bypassing it. Also test your sidestand switch.

 

[JBryan91]

Maybe he did that to bypass the clutch switch, thinking that's the problem. Put bike in 2nd gear and roll with clutch pulled in. When you release the clutch you should feel clutch engage. If so, clutch is good at least.

Otherwise, test that starting circuit cutoff relay or try bypassing it. Also test your sidestand switch.

Where is that circuit cutoff relay? left side behind the faux cover? I will test all when i get home.

 

[maleko89]

Check post #5 here: Starter Circuit Diagram Problem`

Once you find it, test DC volts coming out of red/white wire while neutral. S/b 12 volts. It should stay 12 volts with bike in gear, side stand up, clutch pulled. If not, it's the cutoff circuit that has an issue.

 

[TK3333]

Try engine off, in gear, pull in clutch and try rolling bike back and forth to see if clutch is disengaging. If bike wont roll the clutch mc and/or clutch slave may need rebuilt or replaced.Try kickstand up, bike in gear, clutch in, press start button, if saftey circuts are working the bike will turn over. If it fires up put kick stand down and it should cut off.

 

[MaxMidnight]

If I'm understanding you correctly the bike starts OK, you pull the clutch in and as you select gear it jumps forward and stalls?
IMO this has nothing to do with the safety circuits.
If the bike hasn't moved for some time then over time the plates ring (stick) together and give the symptoms you describe. THe issue is that the friction plates have not separated fro the steels.
Sometime you can jerk them free by doing what you have done.
If you can't free it off then it is best that you dismantle the clutch pack, lubricate the plates with fresh oil and re-assemble. Note which way they came out and re-assemble the same way. Also check that the plates lift when the clutch lever is pulled in.

 

[Fire-medic]

I had a Barnett clutch on my Kawasaki Blue Streak 500 2-stroke triple and overnight the plates would all stick together. The first thing I had to do the next day when I wanted to use the bike was to start the bike up hold the front brake on and kick it into low at which point the bike would Lurch forward because the friction plates were stuck together. Once the friction plates unstuck from that maneuver I could ride the bike normally during the course of the day but overnight they would stick together so that I would have to repeat that same lock the front brake and put it in gear procedure to unstick the clutch plates.

 

[JBryan91]

Try engine off, in gear, pull in clutch and try rolling bike back and forth to see if clutch is disengaging. If bike wont roll the clutch mc and/or clutch slave may need rebuilt or replaced.Try kickstand up, bike in gear, clutch in, press start button, if saftey circuts are working the bike will turn over. If it fires up put kick stand down and it should cut off.

Pulling clutch in while bike is off does nothing. The bike will not roll whether in or out. Really hoping its not a slave or stuck plates as described by Fire-medic and MaxMidnight.... The slave should still be ok if I'm getting excellent clutch feel in the lever correct? I have had a couple of hydro clutch bikes, just never tore into them.

 

[JBryan91]

Also check that the plates lift when the clutch lever is pulled in.

If not the slave is bad correct?

 

[Fire-medic]

The slave cyl is no big deal to rebuild, I usually just replace with new OEM, and clean and store the failed piece for a 'sone-day' spare. Maybe use a rebuild kit on a flip, if the cyl walls and the piston were not pitted.

Place a newspaper or a split-apart paper bag beneath the left footpeg, and engine area, and see if you collect any brake fluid on it. That's probably the clutch master cyl leaking.

https://www.vmaxforum.net/threads/leaky-clutch-master-cylinder.49569/#post-496244
https://www.vmaxforum.net/threads/clutch-slave-cylinder-replacement.45011/#post-484980
The engine on or off, w/a hydraulic clutch properly operating, the resistance at the clutch lever, and the position at which you feel the resistance should be identical.

I'm with the others who think it's the friction plates are bound to the steelies, and not enough oil is on the friction disc plates. It's only the cost of a clutch cover gasket to remove the cover, the pressure plate & diaphragm spring, and remove the friction disc stack to oil 'em up and replace 'em in the proper sequence. Take not of the alignment marks as mentioned in the service manual.

Start at p. 190 of the .pdf page count
It's chapter 3 p. 66 on the page numbers at the bottom-right of each page.
https://dn790009.ca.archive.org/0/i...ice-manual/yamahavmaxvmx12-service-manual.pdf
An exploded diagram for you.

 

[Incider]

Almost certainly plates stuck together.

 

[Fire-medic]

To free-up stuck clutch plates, we used to put the front wheel against a tree or building, and rev it a bit, and release the clutch.

 

[Incider]

We did that too, not sure I'd want to try it with a vmax

 

[MaxMidnight]

Given that stripping the clutch is a straightforward job then IMO that is the best route rather than risking damage by using 'other' means.
If you do the job with the bike on the side stand you won't even loose much oil.

 

[BHZ]

Hello all new to the forum here. Recently acquired a 95 vmax from a guy locally here in Texas. The bike sat for bout a year. I had the carbs rebuilt and put them on the other day with no issues. The bike runs great. While checking the controls the clutch lever had no positive feedback and went straight to the handlebar when pulled. The reservoir still had a little fluid in it. Cleaned the reservoir and bled the system normally and reversed bled as well. Even bled the air from the banjo bolt by the clutch master. The clutch lever has great stiff feel and operates normally now. The issue I have is that when I pull the clutch lever in and put the bike in gear it jumps forward and kills itself without me ever releasing the clutch lever.

Any Ideas??

P. S. I did use the search function first and could not find an answer to my issue. Majority of it was "proper" bleeding procedures and full clutch rebuilds/mods.

TIA!!

That happened to my bike from the last guy leaving it sit for 5 years. I pulled in the clutch handle all the way and put 2 spring loaded wood clamps over the handle and grip. (or you could tie it to the grip)... let it sit all day and night.. Next day.. Voila! Worked like a charm! Unstuck clutch!

 

[tjchung65]

I had something similar happen with my 2001 gen1.
The bike bucked like a bronco when I put into 1st from neutral.
I cleaned and rebuilt the push lever comp (#1FK-16381-11 ) with the K&L kit (32-0128)
Of course did a complete drain and bleed of the fluid as well.
Don't have a problem any more.

 

[Fire-medic]

I had something similar happen with my 2001 gen1.
The bike bucked like a bronco when I put into 1st from neutral.
I cleaned and rebuilt the push lever comp (#1FK-16381-11 ) with the K&L kit (32-0128)
Of course did a complete drain and bleed of the fluid as well.
Don't have a problem any more.

That's the clutch slave cylinder for those of you who are unfamiliar with Yamaha phrasing. #27 below. 'Push lever complete.'

 

[JBryan91]

Thank you everyone for the advice. I’m pulling the clutch cover as we speak. I will give y’all an update on what I find.