I am in the process of rebuilding the gearbox on my M 20 .
To my delight the innards seem to work fine now ,all gears engage smoothly .
So I closed up the box by re fitting the inner cover. There is just a tiny little bit of play on the main shaft , which is correct, I believe.Also with re-fitted inner cover gear changes work fine.
I can however not get the work the box as intended when I fit the ratchet sleeve plate. Much head scratching and foul language ensued. I have now found that I am missing the "spring loaded plunger" a.k.a "gear control index plunger sleeve & spring". ( part nrs 154223 and 154225 ).
Could this be the cause of my woes ? I ask as I can not see what it is doing or what it is for . If so , is there a way of improvising said part ? I live in Thailand and parts availabilty for M 20's is a little limited here .

Many thanks in advance and greetings from sunny Phuket

Maxim Jurgens

email (option): siamsailing@gmail.com

The plunger engages a small recess in the rear of the kickstart ratchet plate and ensures that the mechanism returns to the 'central' position after gear changes....

It's about 1/2" long with a point on the end which is then rounded off slightly to suit the recess in the back of the ratchet plate...

The spring fits into the holder located in the inner cover, behind the ratchet assembly and then the spring is fitted...

If you make the parts do not put the plunger into the holder before the spring...It can get stuck and is then hard to retrieve...

The spring is small (to suit the diameter of the holder) but quite strong so that it exerts reasonable pressure on the plunger....You may have to experiment with that...

Note however, you won't get a really good, clean gear engagement with the box static...It needs to be run for inertia to help the engagement...Ian

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

I think Ian meant selector ratchet plate not kickstart.

Thanks Matt..Your absolutely right!...Ian

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