Weird clutch

[Worty]

Cheers CB.  I'm not sure how the sleeves work, but if I was adjusting on the engine sprocket, it would have to be nearer the inner primary rather than further away.  My logic says that if you make the oil seal sleeve thicker, it'd move the sprocket away from the inner primary cover rather than closer to it??  As it stands, the chainwheel is too far in or the sprocket is too far out (by around 3-4mm)

[morris]

Are your kinked gearbox plates the right way round?

[Worty]

Are your kinked gearbox plates the right way round?

They should be Morris.  I did get them mixed up originally but nothing would fit together.  I looked into it and everything went back together fine.  Can't remember offhand which side they went on, but I believe it was primary side and both kinked plates were on the same side - can check though.

Just can't see how too get the engine sprocket closer to the inner primary cover without risking snagging the chain.  On the other hand, how does one move the chainwheel out when all is located correctly??

[Catz]

My twopennethworth, has your engine sprocket got a shoulder on the back which will push it further away from the chainwheel? Mine had until i ground it off.

[CheeserBeezer]

Cheers CB.  I'm not sure how the sleeves work, but if I was adjusting on the engine sprocket, it would have to be nearer the inner primary rather than further away.  My logic says that if you make the oil seal sleeve thicker, it'd move the sprocket away from the inner primary cover rather than closer to it??  As it stands, the chainwheel is too far in or the sprocket is too far out (by around 3-4mm)

You are correct.

[Worty]

My twopennethworth, has your engine sprocket got a shoulder on the back which will push it further away from the chainwheel? Mine had until i ground it off.

Hmm Catz, you may have something there, I will check tomorrow.  Do you know if the original sprockets had shoulders?

[Catz]

My twopennethworth, has your engine sprocket got a shoulder on the back which will push it further away from the chainwheel? Mine had until i ground it off.

Hmm Catz, you may have something there, I will check tomorrow.  Do you know if the original sprockets had shoulders?

I think the originals are flat and then thin shims are used to space them out. I've seen three types of sprockets from the flat to the slightly shouldered to the quite pronounced shouldered. You'd think they would be of a set thickness but who knows why.

[Worty]

This is very interesting, thanks Catz.  I will check with Bergs (who built the motor), and check myself.  It would make sense if a shouldered sprocket was on, that would account for the difference (at least in part).  If I changed the sprocket to a flat one, do I need to change anything else on the cush drive?

[Catz]

Look at this diagram form Andrews website> https://sites.google.com/site/priorymagnetos/primary-transmission---4-spring part number 67 - 1138
It's called a distance piece and i had it the wrong way round and it took ages to suss it out but with Andrews help i got there. It goes in one way and has a taper which helps to line it all up.
You could have it the wrong way round.

[berger]

it aint the wrong way round me duck i put it together, worty i can't remember about the sprocket but it could well have a nice thick shoulder that is causing you grief, take it off and have a butchers .

[berger]

Catz is was the wrong way round when i stripped worty's absolute nightmare engine that myself and my brother sorted out for him. take a look at worty's engine strip and worty's engine rebuild .

[Worty]

it aint the wrong way round me duck i put it together, worty i can't remember about the sprocket but it could well have a nice thick shoulder that is causing you grief, take it off and have a butchers .

Going to have a look tomorrow or Tuesday mate, surely it has to be shouldered to throw it out that much??  I wasn't aware of this issue when I put it back together after the rebuild, but it's clear it needs to be addressed because of the uneven wear and damaged chain!

By the way, in the pic you posted, does it show RM's cock up of putting it on the wrong way round?

[berger]

worty that is your crank how it was put together by RM

[Colsbeeza]

Worty, I had the same issue with the engine sprocket away from the engine by 3mm for my 1961 A10. My new cush sleeve bearing (42-0069) had a shoulder thickness of 8mm, so I machined 3mm off it for a final thickness of 5mm. Draganfly has three Part numbers for the S/A cush sleeve bearing (attached). My new 21 tooth sprocket has a shoulder thickness of 1.87mm, so I left that alone and just took metal from the sleeve bearing flange. The spacer which Berger put on the correct way round is 10mm thick if I remember rightly.
John Chaterlea's excellent article below covers this issue and the clutch centre issue very nicely.
                  https://www.a7a10.net/forum/index.php?topic=9646.msg70166#msg70166
Col

[Worty]

Cheers Col!  I've been through John's post which is very helpful in understanding the issues.  The next step for me is to take it apart, do some investigation and measuring up, then take it to Bergs who has very kindly offered to help sort it with MWAS.  To tell you the truth, I'm relieved that these are problems others have had and found a solution to.  When I first discovered the issue (and damage), I was scratching my head.  Clearly, RM never had a problem with shoving it all together without checking these things!