Hi everyone, I'm a newbie here,hopefully someone will be able to give some advice.
I got an M20 about 6 months ago, just got it MOT'd. Very next time I go to start it the kickstart just slips round without engaging. If I do it gently, but not fast enough to start it it does 'grip'. I imagine its the shock loading it cannt take. From the looks of the parts list its the kickstart quadrant that has gone. Question is do I need a new kickstart pinion as well or will I get away with just the quadrant. Also is it hard to do? I have done a bit of spannering on bikes over the years but nothing on an old BSA? Thanks.

Does it make a rattling sound, or just slips?
If it rattles, have a look at the engine cush drive, the cush drive nut might have loosened!
DAMHIK...

email (option): viaconsu # planet dot nl

Hans is right. Also it could be the clutch slipping? Might be time to take the chaincase off for a look see. Ron

email (option): ronpier@talk21.com

Jim should take his bike to Normandy in June and let us experts have a go at fixing it there

email (option): ahum@quicknet.nl

Thanks for the ongoing help guys, I'm a complete novice with these. The noise sounds 'ratchety' and comes from just inside the case by the kickstart. Am I right in thinking that the clutch is on the opposite side of the engine. It never has had any clutch slip before. Thanks again.

Hey Jim,

Henk has a great CD with the workshop manual on it. You can find it under "parts for sale". I would strongly recommend getting it, as a quick read will give hours of riding pleasure in return as you can get your bike fettled. Cheers

email (option): britool51@hotmail.com

And have a look at the 'Technical info' page of Henk's website; there's a wealth of information available!

email (option): viaconsu # planet dot nl

Am I right in thinking that the clutch is on the opposite side of the engine,
Yes Jim your right. The clutch is under the primary drive case on the left hand side of the bike. You have to take the cover off and the clutch is under the round cover. I MUST warn you that getting the clutch and putting it back again is a real pain in the A**e. So i hope that it's not that.
Dave

I wouldn't start with the kickstart quadrant...Check first that the clutch is correctly adjusted (at the operating arm end, or front cover end, of the gearbox)and you have free play in the cable and it is lubricated correctly. If you then still have a problem drop the primary cover off and check the crankshaft shock absorber. If that is OK take off the cover that is fitted over the clutch and check to see if you have clutch slip. Lastly, if all of that is good go for the kickstart quadrant...which is probably the least likely of your potential problems.
If you have to strip the clutch you will require two special tools..one to remove the clutch sleeve from the gearbox mainshaft and one to compress the clutch spring when replacing it.
The manual is really an essential you should acquire before you start...Ian

remove the clutch cable from the clutch arm completely and see if this cures the problem if it does it might have been badly ajusted or the wrong length cable

Thanks folks, looks like I am going to have to get the manual or CD, I have a Haynes manual for the 54-61 bikes which has a section on the M20 but its not very explicit.

i too would suggest checking your clutch cable. Also removing it and trying again I had the exact same experience. I did everything backwards though. Checked cush drive then ratchet and then the clutch. The whole time it was the clutch cable hung on something.

email (option): micran1234@yahoo.com

It's a process of elimination until you get enough experience to identify the problem right off...so always start with the things that are easiest to do, and and to access, first... ....Ian

If you continue to try starting it, or get it started and run it with the shock absorber lose enought to make "the rachet noise", I beleive this will cause the clutch inner and outer drums to "groove", which will give you drag/slip problems in the future
DAMHIK

The best way to prevent the cush drive to loosen is to install a lock nut. Find a 3/4"x20 nut, and round it off in the lathe so it will fit in the recess in the retaining nut. Then drill two holes to fit one of those special 2-pin tools; you can buy one, or improvise of course.



When properly tightened mark the locknut and the retaining nut with two opposing punch marks, to signal any loosening of the locknut.



And also acquire a hook spanner for the retaining nut, so you will NEVER EVER have to use a punch/screwdriver/chisel to tighten that nut!

email (option): viaconsu # planet dot nl

I sometimes fit a crankpin nut to the mainshaft as it has the same thread. I fit the nut with the flat side facing outwards.and just use a socket and wrench to tighten it up. Alternatively one of these nuts could be machined down to produce a 'Hans' conversion!..Ian

email (option): jeff@infinitymedspa.com

Jeff I know it's a pain with all those 2BA screws against your paint! But worth removing the chain case for a look. It's surprising how quickly the cush drive nut will come loose if not fully tightened on assembly. I always put some Loctite on mine......It's still easier than taking the gearbox apart.

Ron

email (option): ronpier@talk21.com