Misc: Everything Else Exhaust AND carbs.

[Peter Holmes]

Silicone Fireproof Sealant, Envirograf, Manufactured by Intumescent Systems Ltd, www.envirograf.com

 

[Vincent Brake]

It takes a fair bit of time to get them really square to the head inside butt.

I make up stainless 4 mm high rings with the flange.
And a small bit, interfer fit, into the pipe.
Than hit the pipes into correct position.
Juggle until satisfied. If not a beer helps great here, than take carfully out the next day.
Tag weld, refit with a coat of blue and juggle again, best with a beer than see if it has thrust arround.

Very happy easy to take out and fix pipes afterwards.

Mind you it can take a day

 

[timetraveller]

Ed, I have found that it does not seem to make much difference what brand of silicon one uses. What does seem to be important is that it is clear or generally labeled translucent. Pigmented ones do not seem to last as long although I have not done extensive testing on this. Of course if there are ones available specifically designed for high temperature use the they might be better but the two or three pounds a tube stuff has lasted for years. It will not cost you more than that to try it and a tube is enough to be shared over at least ten bikes.

 

[Chris Launders]

I have a V-twin JAP SV with a persistent weep from the rear head, not blowing just forcing oil/petrol through the joint, I was thinking of using high temperature silicon on that.

 

[timetraveller]

Chris, it was something similar that fist put me on to using normal silicon mastic for jobs like this. I was helping a sidecar racing chum at a meeting somewhere and as you probably know many of the sidecar outfits are built by normal chaps racing on a shoestring. This means that they have blow ups and break downs fairly often. During the lunch break I was walking round the paddock and saw some chaps rushing to rebuild the top end of their engine. They had no head gasket but instead they were squirting normal builders mastic around the joint. When I queried this they told me that it typically lasted many races. One of my other interests is boats and over the years I have built, assembled or rebuilt several boats to be used in the Mediterranean, where summer sun and sea air can shorten the life of things fairly dramatically. I have found that bedding hatches in with clear mastic I get at least ten years out of it but if I use pigmented mastic it is brittled within a year. Hence the suggestion to use the clear for the exhaust systems where, on my bike, it has lasted years.

 

[oexing]

Silicon would not be my choice in this place, horrible stuff anyway. Instead I´d put some length of material like used for ex pipe wraps under the finned exhaust nut on top of the flange. That is quite pliable to form a good seal anywhere - and temperature is no factor at all. Whereas silicone is at its limit there. That pipe wrap is something like glass fibre or alternative to it and that kind of stuff is used in heating business in chimneys etc. . Great in the exhaust system clamps on our radial engine as well.

Vic

heat wrap

 

[ericg]

I use this clear silicone stuff to seal "push-in the head" BSA A65s, Triumphs or RE exhaust pipes.
As mentioned earlier it will last for years and doesn't seems to be at its limits at all as it'll come out in one piece when you remove your pipes again. Actually it almost could be re-used.
Cheers.

 

[Albervin]

With all connections sealed there is still a bit of flame on the over-run. So do I raise the needle or fit a larger main jet? Idle is sweet and steady.

 

[Bill Thomas]

When I was working on Jag's, We used a Machine from USA, If I set the Carb's Sweet and Steady, At tickover,
On the road it was Weak !, So I would make the pilot, More rich ?. Cheers Bill.