Hello, my gearbox cover bush has been leaking grease from where the kickstart rod is and I found out that this is because the bush on the cover seems to be imperfect (Marked on the pic). There is lot of play.
Is it a good idea to remove this and then machine a new bush and fix this? What material should I use on this? Please advice.



Tavery Peters

email (option): tavery.p@hotmail.com

They leak anyway. Dont worry about it.

Hi Tavery...The M20 has a hardened steel bush which is ground internally to the finished size. For a kickstart shaft, which bears a heavy load, I think this would be the best solution (if it doesn't already have that). Clearance should be minimal, probably no more than .0005".. half a thou. One problem you may have is wear of the kickstart shaft itself. That cannot be cleaned up and an undersize bush made because it would then be undersize for the kicksart itself.
So, really you need to strip it out first and see what you have. My guess is you might need a kicksart shaft and bush..both of which are available new for the Matchless I think....Ian

email (option): ian@wright52.plus.com

In my case I fitted a NOS bush and a NOS kickstart spindle and still had a play of over 0.5mm, maybe good enough to keep the grease in but I wanted to use SAE50 oil in the gearbox in stead of grease.
I replaced the original steel bush for a bronze one, actually fitted two bushings with a small space between them for mounting an o-ring.



I replaced the original felt seal on the output shaft for a modern one and sealed the open bush of the gear selector drum and the open bush of the gear selector quadrant spindle with expansion plugs.



The gearbox is oil tight now.



Regards,
Peter

Nice job Peter...and the bike is looking really good as well..I always like a high standard of detailing.....I'd be interested to know how well the kickstart shaft bush wears in the longer term....It's always useful to know which mods. work OK and which ones don't ...Ian

email (option): ian@wright52.plus.com

Thanks Ian,

Will keep you updated about the wear of the bronze bush.

Regards,
Peter

Peter, can i say what a really excellent job you have done on detailing your G3L i did a similar oil sealing job on my gearbox several years ago...and that has worked really well... all you need is the 4/5" long external "spring" to go round the Decompressor cable to keep it away from the exhaust...

Ed

email (option): edd@abbottracing.com

Hi Ed..Did you use bronze or steel for the bush?...The reason the 'serviceability' of this mod. is of interest is that at some point the original hardened steel bushes for the M20 (or others thus equipped) will become unavailable...At that time it will much easier to produce a bronze bush than a hardened steel one which is internally ground to the finished size!...Ian

email (option): ian@wright52.plus.com

Hi Ed,

Thanks for the tip, did't know the decompressor cable was protected by a spring.

Regards,
Peter

Peter,

Yes, these are always protected by that spring, it's a square profile material, will ask the spring manufacturer if he can make some, I need some too.

Looking at pictures, the G3L, used tubing???



Here a picture of the spring type (on the wrong side of the pipe!):



Originally they were cad plated.

Cheers,

Lex

email (option): welbike@welbike.net

Hi Lex,that spring material looks like the outer of a speedo cable with the
plastic removed.you will have to see if it will fit,may save you a few bob.
cheers rick

email (option): richardholt@rocketmail.com