Motorcycle Repair: Yamaha clutch, conversion vehicle, clutch basket


Question
I bought a Legends car and it's got, I believe, an FJ1200 motor and with the motor running I engaged the clutch and it won't go in gear without force. Then it gives a big jerk and clang. Without the motor running, I push the clutch in and the car will  not free-roll in gear. Have bled the slave cylinder and looks to me like long rod going into motor is traveling the full distance it should.
 Can you tell me what's wrong? Any answer would be appreciated.
Thanks much,
Larry

Answer
Hi Larry.
 Well, it seems to me that as long as the clutch has been properly bled there should be no problem.

Since there is a problem then there are only a few things that it could be.

1)  There is a naturally occuring reverse trap in the hydraulic line which is not allowing the system to be properly bled. Remember that air will always want to travel up a hydraulic line and if there is some high point between the slave and master cylinders, then air will trap itself there, preventing proper bleeding. Since this is a conversion vehicle you will run into these kinds of problems.  Homebuilt aircraft pilots run into the same kinds of problems.

2)  The clutch pushrod is Worn, warped, bent or broken.  This will prevent full engagement of the clutch by not being able to fully extend the clutch basket.

3)  The clutch and/or transmission needs rebuilding.  Remember that this is a motorcycle engine which has been placed in an automobile.  The stresses placed on the drive train, clutch, transmission and crankcase are radically different from it's designed purpose.  This motor was designed to move a 600 lb motorcycle and a couple of people, not a 1/4 ton car with occupants.

If it is none of those things then I have no idea what else it could be.  Your next step at that point is to try to find a group on the web that specialises in that particular vehicle.  They will be more aware of any conversion-related problems than I will.

Good luck.
FALCON