Hi All,

I know this is an M20 site but Danny DeFazio of Sump Magazine recommended I tap into the collective knowledge on this site as I'm failing to find any anywhere else.

I have a 1929 500cc Twin Port Sloper that used to belong to my grandad which I regularly use. It recently had a real gearbox moment that locked the whole thing up. Now I've taken it off it seems to be ok again and that's left me rather puzzled and in need of an expert view. As well as a couple of parts.

Can anyone recommend a specialist in the UK who would be able to help me for not silly money?

Many thanks in advance
Anthony

email (option): anthony.j.jenkins@barclays.com

Only to reasons why the box can lock up
1) two gears selected at the same time
2) gears meshing too deeply.

Of the two the first is most likely and is caused by wear which is usually greater in the lay shaft gear change fork.
Your forks are identical so measure both of them.

Generally the top fork ( layshaft ) is the one that gives ou grief as it gets less oil than the mainshaft one particularly if the oil level has been allowed to drop a bit and even worse if you have been using liquid grease to stem the flow of oil out of the drive.

The other common incorrectly changing problem is due to wear on the thrust faces of the top hat bushes giving too much end float

The less common cause is the main shaft shifting left right as there is not much retaining it and pounding on the shaft to remove a clutch can actually move the shaft.

Meshing problems are generally due to wear in the shafts & bushes and again the lay shaft is the usual suspect and as per the previous this problem is exagerated by the use of thick oils & liquid grease

email (option): wariron@tpg,com,au

OK ,
3 reasons I forgot things like foreign matter ( bolt or broken tooth ) getting jambed between teeth but as it runs again I sort of ruled that one out.

You might like to give the V-twin forum a buzz as well.
They do a lot of off topic posts and slopers are right up their path.
https://groups.yahoo.com/neo/groups/bsavtwins/info

email (option): wariron@tpg,com,au

That site is pretty dead. I check it every day and nothings happened in months.

That site is pretty dead. I check it every day and nothings happened in months.[/quote]

Well how many V-twins are there out there ?
And it is not the volume of traffic that is important it is the quality of the traffic.
Every time some one puts a question there they get good answers fairly quickly.
Take out the ride threads , the dating threads and the rest of the off topic threads then this site would be fairly dead as well.

And I check it ever coupe of days as well they are a geat group of owners dedicated to killig off the elitism & snobbery around the BSA V-twin owners which used to be a bunch of morons dedicated to keeping as many bikes as possible off the road in order to maintain the value of their motorcycle investments.

email (option): wariron@tpg,com,au

Many thanks for the reply Trevor. It turns out that the mainshaft at the top of the box had been getting pretty hot over the years and eventually this result in some highspots forming on the main shaft which inturn meant the 3rd gear dog seized onto it rather than spinning freely. The whole gearbox then had a moment, broke the tooth on the 2nd gear and the rear chain. I'm amazed it didn't do more damage to be honest, strong gearbox that! Anyway, Ian at Verralls found a replacement gear and after a quick smooth down of the mainshaft with a stone on the lathe all is well again.

Your point about lubrication was well made and I'm going to use a mix recommended by the nice man at Morris Oils from now on.

Important lessons learnt all round for me.

Now, if I can only find a new kickstart quadrant (15-4051) somewhere I'll be laughing.

Many thanks again
Anthony

email (option): anthony.j.jenkins@barclays.com

Is that kick start quadrant much different than the one on a BSA m20 ?

De Groot ?
I think do quadrants for slopers.

email (option): wariron@tpg,com,au

Is that the quadrant that looks like an M20 one, but has the cotter pin groove in a different position relative to the teeth?....Ian

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