Motorcycle Repair/Cluch problem

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Question
Hi,I have a 1981 Honda CB 900f and problem with the couch. When bike is running in neutral if I pull the cluch  lever in and select first gear bike will jump forward and stall immediately. When the bike is not running I can select any gear and if I try to push it with cluch lever  pulled in it won't  go? What to do?

Answer
Hello Nino,

First of all, in order to troubleshoot accurately, I need some information.
Did the problem occur after any kind of maintenance to the engine (clutch plate, clutch cable, clutch lever replacement, oil change, clutch hub adjustment)?
Have the bike been sitting for a long period (more than 10-12 months)?

How much is the clutch lever free play ? Have you tried to reduce it by means of the clutch cable adjuster?
Do you feel adequate resistance when pulling the lever in?

Try the following:
First give the clutch cable as much slack as possible by the adjuster.
Remove the cap, located in the center of the clutch cover. You will see a flat-screwdriver-bolt with a locknut. Loosen the locknut (must be a 12mm hex if I recall correct) far enough for the bolt to turn freely.With a flat-head screwdriver turn the bolt clockwise until you feel resistance and from that point turn back (counter-clockwise) half a turn. Hold the bolt and tighten the locknut. Close the cap, adjust the cable to 2mm free play and give it a try...

The following apply only if the bike's been sitting for a long time:
Maybe it's just a matter of clutch plates stuck together. To eliminate this possibility, start the engine and let it warm-up to working temperature. Hold the clutch lever pulled in, and rev the engine to 2500-3000rpm for 3-4 minutes. Stop the engine, lift the rear wheel of the ground, select first gear and start the engine again. Rev it to 5000rpm and holding the clutch, apply sudden strong "kicks" to the rear brake several times. This should do the trick if it's a case of sticking plates.

If the problem occurred from one minute to the other, it is either the outer clutch hub bearings seized, clutch plates warped and/or broken, or, clutch disengage mechanism malfunctioning. These require removal of the clutch cover.

Get back to me anyway, to let me know which of the above apply, so I can guide you more accurately.

Best Regards,
Lazaros.  

Motorcycle Repair

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Lazaros Ampatzidis

Expertise

I can help you on EVERY issue involving POST-1980 Japanese Motorcycles plus KTM and Husaberg. My field of expertise includes Engine, Transmission, Fuel system (carburation & EFI),Electrics and Electronics. Maintenance, repair and tuning. Road and off-road suspension tuning. Please don't ask me about non-Japanese Motorcycle, especially American built on which I have low to zero experience.

Experience

I'm a rider and hobbyist since childhood. 25 years motorcycle workshop mechanic.15 years motorcycle racing mechanic. In order of experience high to low:Kawasaki,Suzuki,Honda,Yamaha,KTM,Husaberg.

Education/Credentials
Hellenic (Greek) Technical School.Internal Combustion Engines Engineer. Automotive Electronics.

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