The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Goldy on 05.10. 2011 15:55
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The 56 A10 has an oil leak ( so what,s new). After a run there are spots of oil on the top of the chain case to the rear. The top of the timing cover to the rear and the top of the magneto. The base of the barrel seems dry but some of the fins are wet. Any suggestions would be appreciated. Regards Goldy.
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The crank case breather is between the crank & drive sprocket.
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Hi Goldy, my A10 has a leak from the rockerbox which I'll do over the winter. The oil spots after a ride ,are the same as yours, chaincase,in the dip of the timing cover ,on magneto and round the fins.When run in shed just runs down fins . Check also the rocker feed connections,fibre/special washers even the feed pipe may have a leak, could be something as simple as this,hope so regards BobH.
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Thanks topdad, it,s somthing to do in the winter months.
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I've had issues with rocker box leaks of late, thought I'd cured the thing when it sprung another on the opposite side.
Closer examination shows the gaskets are not cut correctly and don't cover the two mating surfaces fully, in fact just about an 1/8th of an inch or even less has gasket between the rocker box and head, I got some cork ones from Ebay (was it one of you?) but only for the big gasket so have ordered some cork sheet to make the smaller one from.
For the mean time made my own.
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HI Bill,
I dont believe "cork" gaskets will be any good in this location
Cork needs wide surfaces so the pressure per sq in. is low
The rocker box tends to cut and squash out even the "normal" gaskets
If you can get some "klingerite" gasket material 0.5mm thick it will be a lot better
You need some sharp tools to cut this cleanly
HTH
John O R
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Cheers John I'll look that stuff up.
As for sharp tools needed I have two fingers and one thumb to testify that my ALDI craft knife kit is sharp enough *doh*
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Forget the cork as others have said it will not work in that spot.
The best solution is a copper one from Lanni at <www.coppergaskets.us>.
His prices are quite reasonable and after you fully anneal the gasket it will last a life time.
I get base gaskets ( compression plates ) & head gaskets cut there all the time.
He should have the rocker gasket dimensions if not you send him a scan , photo , rubbing whatever yu like & he will send you back a gasket that is a work of art & perfect fit.
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Hi Trevor and John
Wish I'd mailed in before I bought the sheet of cork, but I'm sure with two A10s I'll find uses for it.
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Ditto Trevor's post. Lanni also made me some special head gaskets to suit my through bolting, $22 each landed. He adverts the rocker box ones on ebay from time to time.
Cheers
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Copper , thats interesting. How thick is it, I assume it,s thinner than the head gasket.
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G'day Goldy,
I think mine are 30 thou", but he can make them in any thickness up to 1/8".
Cheers
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Hi there
Just reading this post and above someone is advocating obtaining some Klingerite gasket material I used to use this some years ago at work for explosion relief panels it makes great gaskets but be warned it is asbestos based.
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Hi Bob,
"Klingerite" is basically a trade name, Asbestos gasketing has been outlawed for nearly all aplications for a long time
The gasket type material I am referring to is probably madee by several manufacturers
My local stockist for gasketting are "James Walker" and co
Anyway, the material I am on about has one side graphited the other matt, Its very much akin to the material in japanese bike gasket kits
Cheers
John O R
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Hi All,
I sent an email to Lani about the copper gaskets, he has replied saying he can supply the rocker cover set at .81mm he offered diffrent thickness gaskets. Is .81 mm thickness ok?
Thanks
Duncan
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G'day Duncan,
0.81mm = 32 thou". Should be OK, just check the position of the tappet adjuster at 1/2 lift. It should be in line with and center of the valve stem. Thicker will move it in, thinner out. But not that critical on a road motor.
As Trevor said, they must be annealed properly, heated to red and quenched.
Cheers
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Many thanks Muskrat