One thread or two? (gearbox camplate plunger)

[brackenfel]

As paranoia levels increase while I prepare for the reinstallation of the gearbox - is everything right?, did I tighten that bit up? etc one little doubt nags at my limited brain.....

The camplate plunger has all been cleaned up and reinserted.. The question is , how many turns of thread should be visible when you tighten up the locknut?? A10 Haynes manual says two  but the Haynes for the B33 says one (same box!), "Humbernut" in RC magazine says one, an older mag featuring a Goldie box rebuild says one... How crucial is this?? At present I've got a generous 2 threads showing & everything seems to work.. I don't want it too slack but then again I don't want a stiff gearchange either.

Any thoughts / tips ??

Thanks,
Adrian

[muskrat]

G'day Adrian,
                      I don't think it's that critical. Mine worked OK with a few threads showing. If your worried split the difference and go 1 1/2.
Cheers

[alanp]

Adrian, agree with Muskrat. I've seen big variations between boxes and particularly plunger pin/pin housing/spring condition etc etc so start with one thread, see how it changes. If the lever seems to need more force to change gear than you expect, try backing off another thread or two. Don't test it with the bike stationary/engine off, it may block a gear change and fool you. Try it with the bike on it's centre stand and engine running or on the road.   

[brackenfel]

Thanks Alan & Muskrat,
As suggested I've "split the difference". The wife was out for the day with a friend so you can guess where I was... 

Gearbox is back in (yes, you can remove it without touching the engine, but it's fiddly!). Chain threaded thru the dreaded FERC front part , but I can't find the split link now!!.
Have started assembly on the primary side so progress is finally being made.. One further question though (sorrry!) when tightening up the nut on the engine sprocket / cush spring do you tighten it right up or just until you can get the split pin in??

Cheers and thanks for all you help - don't know where I'd be without all you guys on this Forum!

All the best,

Adrian

[muskrat]

Tighten it right up, I think 65ft/lbs is the figure which is real tight. If it is loose it will flog out the main bearing and shims.
Cheers

[brackenfel]

Thanks Muskrat, I'll get the torque wrench out!!
I've also found the split link & clip (in 2 separate tins!!) so no need to wait for another!! Now I find the original woodruff key doesn't fit the better mainshaft I've substituted which has a perfect keyway, time to get the file out..
Don't you just love these things - I think mine has developed an attachment for the garage & is now doing it's best to prevent me from taking it out!!!

Cheers,
Adrian

[brackenfel]

Hi Muskrat,
Sorry - have another question related to the engine sprocket cush drive nut.. There's a tab washer that I have a new one of, the Haynes A10 manual doesn't mention fitting but the B33 one does. It's been so long since I took this thing apart I can't remember - do the tabs on the washer face the splines or (as I suspect) back towards the nut to locate in the 2 slots??

Thanks for your patience!!!

Adrian

[muskrat]

G'day Adrian,
                      I have never used one but I'd say the inner tabs face the spline and the outer tabs fit the slots.
I had to dig out the parts book to check.
Cheers

[wilko]

Elementary my dear Watson!!

[brackenfel]

Thanks Muskrat,
In fact there are only one set of tabs which only face one way so I'll leave them towards the splines - I'll just tighten it up hard & maybe punch the outer edge into the slots on the nut if I can get in there!!

Chers,
Adrian