Gearbox main shaft

[Craigy]

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[Craigy]

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[Craigy]

Rubbing to rear of primary case

[BSA500]

Sorry to me that inner primary case looks too close to the gearbox. I dont even have that spacer on the A7 and the space and alignment of the chains, primary and final are fine. Why not try it as a dry build to check out clearance etc

[Craigy]

John,

I realise why my previous post about the spacer doesn’t make sense now.

I’ve taken the rear cover off the bike again and now realise that having a spacer at the rear would make no difference as there is nothing for it to ‘push against’.

Sorry for the confusion, it’s not easy being this thick 🤣

[chaterlea25]

Hi Craigy,
You have me confused now too 

I thought that it was the primary chain was too close to the rear case?
I was asking how far the adaptor( clutch center )sits onto the main shaft ?
Referto my article for a measurement (16mm?)
The adaptor rear scroll dictates the position of where the rear primary case should be, the scroll should be almost fully engaged, sometimes a felt washer sits between the adaptor and sliding plate, not to be confused with the large felt seal between the sliding plate and rear case.
The spacer you have fitted between the chaincase and frame looks fairly thick?
I would remove it, then bolt the inner case and it's spacer plate to the crankcase, use spacers to temporarily fit the front screws
Now measure the gap between the case and frame, along with checking the engagement of the clutch (adaptor) center if all is good use some washers to fill any gap between the two

John

[Craigy]

Hi John,

I realised we were on different tracks 😁. No hassle.

One of the guys from club had a look for me yesterday and said the same about spacer size, I have replaced with a couple of washers which have given me enough clearance for the main chain behind the inner case. (I didn’t measure but reduced from approx 10mm to 5mm).

I’m just in the process of putting back together, all good so far. I’ve got the Cush drive and clutch basket etc back in place….just need to put plates back in, primary chain on, check front casing.

From what I can see, I haven’t altered the alignment of the shafts so all should be good there. Nothing is catching so far.

I’ll let you know how I go

[jhg1958]

Craig’s

I have just taken my primary chaincase off so i thought i would do some measuring.  It is a bit hard but i did my best. 
From the back plate of the chaincase to the end of the main shaft is 42mm (yours is 37mm)
From the oil seal to the end of the main shaft is 48.1mm

From the oil seal to the inside of the rear chaincase is 8mm

I can do more measurements if you want.

My spacer (washers) is 5.5m,




Looking

[Craigy]

Thanks very much for bothering to do that 👍.
Unfortunately the bike is nearly back together.
I took the spacer out, approximate measurements are spacer was 10mm and appears to be homemade. I replaced it with 2x washers which measure approx 5mm.
I did some searching last night and found Draganfly list 2x washers/spacers measuring 1.02mm (0.40”), I also found an old post by John from 2016 where he mentions adding/removing spacers if required.
So far everything looks good. I’ll bench test it/and a run up the road before I put the outer cover back on. Previously I had a 3mm (rubber) gasket made as I had a bit of fouling going on inside, so I think that will work in my favour if there’s any flex in the casing

[Craigy]

Just measured the spacer…..6.5mm and not square……2x washers measure 3mm

[Craigy]

Hi guys,
I’m in another quandary, but have kept under same post as the ones who have already been good enough to answer are aware of the problems…..

Seems like I’ve sorted out the spacer/drive chain rubbing problem. On putting everything back together, the kickstarter was really stiff and not getting anywhere enough speed to kick the bike over.
I’ve started stripping it down again to recheck everything


Kickstart works freely when no primary chain attached. In gear turns rear wheel, in neutral it doesn’t.
Primary gear and clutch basket spin independently and together with clutch engaged or not. Clutch cable is currently disconnected.
I’ve taken Cush drive off again to make sure all was good there……only gear, spring, nut - so I reckon I’m good with that but can’t turn gear even with plugs out. Is that to be expected? I assume so.

With primary chain connected, bike in 4th gear, plugs out. I can turn rear wheels, thus also primary chain but only get a small turn (maybe less than 1/4 wheel turn) and bike makes a pretty solid clonk. I assume this is when it finds resistance on the crank etc.

Am I missing something pretty obvious? Just can’t figure it out.

Cheers Craig

[groily]

Should be able to rotate the crank easily with a spanner on the shock absorber 'nut' with the plugs out - even with the plugs in for that matter.
If the crank won't rotate, is one of the three screws that retain the inner primary chaincase to the crankcase too long and fouling the web on the crankshaft that side? That would give you the partial rotation then a clonk  . . . .

[Craigy]

You could be onto something……I have a couple of the bolts in without the outer primary cover. The front one to make sure the inner primary cover stayed aligned and the bottom one that stops oil from wet dumping coming out…..can’t wait to get home to check 👍……I really hope so

[Craigy]

Groily,

I think I must have misread your post earlier…..

I thought you were talking about the bolts to attach the outer primary case - I’ve got two of then straight onto the rear case so they would be further through the casing than usual.

Having reread your post I realise that you were on about the bolts attaching the rear casing (the ones with the hole and fastening wire?). These are the same bolts that were previously on the casing with no clearance issues.

Ahh well……

[groily]

No, I was on about the three larger dia ones that hold the cases on at the front round the crank. EDIT - But Yes - if that's the 'rear' thing. Wired, yes, usually. I said 'inner' case because most of the chaincase screws just hold the outer to the inner, not the inner to the crankcase. If one or more of them is going in further than it should - the threaded holes are not blind - (possibly because you haven't got the outer on but have screwed the things right up), then something will foul almost for sure and the engine will turn so far and no further. (Or might turn very stiffly if a screw is not deep enough in to lock it up, but is in far enough to graunch against the web, get mullered and then be a serious pig to get out again. Hope not!)
The screws elsewhere on the case, inner or outer, aren't going to interfere with the rotation of the crankshaft.

This was if I understood your original query - apologies if I didn't!