Hey guys! New to this forum. I'm a fellow owner of a 1990 MC22. I recently have changed my head gasket and done a valve clearance. However, after reassembling and starting the bike it has now made a strange grinding noise. The same noise that a dirt bike would bike when you put the kick start lever down whilst the bike is running. Now, it doesn't make the noise when the crank is moved by hand. It doesn't make the noise when the electric start is active. It only makes the noise when the engine is running. I have also double checked all scissor gears. My mate told me it could quite possibly be them. I have also changed out the starter motor and the starter motor gear that is also a clutch type gear. I've had so many suggestions but I've tried just about everything. I also drained the oil and there is no shaving, chunks or even specs of metal. Before I pulled it apart it was top dead centre and has been through out, except when the cams were torqued down (to wind the crank). The noise is coming from the bottom rear of the engine (i think). Any help is much appreciated. Picture attatched is my race bike. Fortunately, not the bike I'm working on
I did change the starter clutch but I'll post a video up when I get home from work so you can hear it. Very unusal noise.
Welcome. So if you only had the top end off the engine and nothing below gasket level was touched, why would a noise suddenly be in the bottom end. My only thought is that something (bolt, screw, etc) has been dropped down the gear tunnel and may be causing havoc in clutch or oil pump area. Suggest taking the right side off engine and get a strong torch and have a good look.
Yeah I took both side covers off to turn the crank. Reason I took both off was to assess the gearing down there as well. I also have had a look through the bottom, around the clutch and a good look at the gears. Theres no evidence suggesting grinding on visible gears. I've also had a magnetic bolt/washer retreiver in and around the engine to get such thing that has dropped it. My question exactly is that. Why has a noise suddenly appeared down there and why is there no shown damage (missing teeth, shavings etc) Thanks for the reply
Also, please excuse me if this is posted in the wrong section or tagged incorrectly. Still new to all this
I've been told this by a few people now. That's the reason I changed it out with a spare. Maybe my spare is buggered as well. It was in my other race engine however but whos knows. I'm gonna try get a few more suggestions before I start buying new parts though.
Hey guys. I'm about to upload a video on my YouTube. I'll be able to share the link to this page asap. Do you guys think a scissor gear could make such noise?
yeah sounds starter related...like slipping or skipping...have you tried bypassing the starting circuit and just spinning starter motor?
Ive swapped starter and also changed starter clutch. Is there another component I should be looking at?
Not to my knowledge, no. I'm constantly pulling this thing apart and putting it back together. So I'll have a look again
It sounds like (to me) the motor slows and starter pitch changes with the noise...like a solenoid/relay is crapping out due to much current draw...or its not meshing right and the teeth are skipping....Clutch basket tight and running true?