Author Topic: M20 kick start issues  (Read 399 times)

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Jamesstrathdee

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M20 kick start issues
« on: 06 November, 2020, 10:32:27 »
Hi, this bike was supposed to be in running condition, it kicked well once and now just sounds like this? Any ideas? It doesn’t seem to be engaging

Jim S

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Re: M20 kick start issues
« Reply #1 on: 06 November, 2020, 13:27:00 »
Is the engine turning? If yes, then you have lost compression maybe due to a stuck valve or a fault with the decompression mechanism.

If the engine isn't turning, I would start by pulling off the primary cover. It could be a broken primary chain or the clutch assembly is spinning on the gearbox output shaft or ...

GLENN

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Re: M20 kick start issues
« Reply #2 on: 06 November, 2020, 13:28:01 »
Hi there, It does seem to be engaging as it sounds like I can hear the compression through the carb and the back wheel is turning.  If you put it in gear can you bump start it?  Sounds like the return spring or something is rubbing on the kick start qudrant.  Easy enough to remove the gearbox cover and check out what's happening in there.  All the best, Glenn

Jim S

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Re: M20 kick start issues
« Reply #3 on: 07 November, 2020, 15:04:22 »
In my post above, I should have written gearbox main shaft not output shaft.
Anyway, looking at your video again, when you kick it over, the gearbox main shaft is turning and by viscous drag within the gearbox, the gearbox output shaft is turning causing the wheel to turn.
Are you sure the engine is turning? If it is, you have very little compression based on the apparent effort to kick it over. Or maybe you are kicking it over with the decompression lever activated??
There is an inspection cover on the primary (left) side. When you remove the cover you can see the primary chain. When you push down the kick start, does the primary chain move?

Rog1

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Re: M20 kick start issues
« Reply #4 on: 08 November, 2020, 01:11:53 »
Another way to see if the engine is turning over is to remove the points cover on the magneto. You can then see if the points are rotating when you kick the bike over.

DANFINN

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Re: M20 kick start issues
« Reply #5 on: 18 November, 2020, 12:23:18 »
Seems to me your kickstarter is not working at all :-\

I have to use a decompression lever to get mine to turnover and then it skips, so I think there maybe some gear damage and am taking the gearbox out to check it over.

The previous owner said he got 65mph out of it and it has not run since, both primary chain and drive chain were taught, no play at all ::)

I'd have a look at your primary drive, see if its all turning
1950 M20 Much fettling needed
1953 M21 loosing parts to above M20
1967 C15 oily rag but runs well
1962 Ariel Golden Arrow, needs a lot more work