Matchless G9 Crankcase oil leak

Biscuit · Post by **Biscuit** » Mon Jan 17, 2005 8:29 pm

I'm probably going to be dogmatic and get myself into trouble, BUT that paper gasket is ridiculous, to interpose a gasket in what is essentially a metal to metal joint MUST be bad practice. I experimented with a machine vice, a dial gauge and a thin paper gasket, 4 thou. thick and the most I could squeeze it down to was 2.5 thou. which of course leaves this gap around the gasket - there's the leak. that is the reason why I elected to fit a complete gasket (not paper) this also cured the leak between the cylinders.

Keith, I'm afraid I don't do these jobs for money, just for a few close friends, even that takes up a considerable amount of time - sorry.

lawrence · Post by **lawrence** » Mon Jan 17, 2005 10:36 pm

I could be your friend Alan [:o)]

(apologies to whichever film that quote comes from)

Lawrence [}:)]

Eric · Post by **Eric** » Mon Jan 17, 2005 11:18 pm

Alan whilst I agree with you that just using a local gasket can create a problem nearby it is much thinner than 0.004" more like 0.002 if not paper what did you use?

Biscuit · Post by **Biscuit** » Thu Jan 20, 2005 7:59 pm

Eric, I used the thinnest gasket I could find, a BSA cylinder base gasket, and I gripped a smaller area in the vice than that of the AMC gasket. However thin the gasket is, it's not going to squeeze down to zero.

Eric · Post by **Eric** » Thu Jan 20, 2005 11:46 pm

Sorry Alan I have just realised I worded my last response wrongly. I was trying to say I agree the local gasket could create a problem but you said earlier you had made a complete gasket (not paper) it is that one I was interested in what did you use?

Biscuit · Post by **Biscuit** » Fri Jan 21, 2005 4:39 pm

Eric, reading your post again it makes sense, I probably didn't read it properly. The jointing I used was 1/32" thick Klinger-Sil, but Klingerite and Hallite do just as well.

lawrence · Post by **lawrence** » Fri Jan 21, 2005 7:19 pm

I tightened my dynamo drawbolt and my leak has disappeared. Well, that one anyway ;o(

Lawrence [}:)]

RogerNorman · Post by **RogerNorman** » Sun Jan 23, 2005 7:48 pm

Alan I would have thought you would have remembered that I had an O ring groove machined into my crankcases where the oil filter tunnel sits when I had the series of three engine outs before the Auxonne International but then perhaps Joe did it. I don't run a paper gasket anymore but I don't have an oil leak anymore either - at least not there. We won't talk about the Greenlane machine however - that will just never go rusty with the outside oiling system!

Eric · Post by **Eric** » Mon Jan 24, 2005 9:12 pm

If you saw one of earlier posts on the subject I had suggested a groove all the way round. Putting that aside what do people have to say about the various sealants. My own experience is with Wellseal, Blue Hylomar or for my more modern device Honda Bond a sort of rubber solution that goes off to leave a rubbery film.