Hitchcocks Forum

Hi there,

I have noticed an exhaust gas leak where my exhaust pipe on my Bullet 500 joins at the cylinder head,can anyone advise on a fix,thanks ,Mike

Yes Mike, take the pipe off and clean it and the exhaust port well. Then use ordinary bathroom sealant to bed it in as you replace the pipe. Unlikely I know but it does work.

Hi Mike, I assume you mean the classic engine with the slip fit pipe, not the bolt up flange with gasket.

I have tried the exhaust paste and to be honest with the vibration and expansion/contraction of the pipe it doesn't last more than a few hundred miles..
The best most of us have found is humble silicon, as in bathroom seal, or the more specialist high temp stuff at a price..

Clean the port and pipe outer and apply a thin smear to each.. reassemble and leave overnight to cure.. DO NOT be tempted to start engine and speed process,

It works, did mine over a year ago and still holding.... gwilly

Here is what's used by our contractors for fitting Exhaust manifolds and exhausts headders on our large diesels I managed to find a tube they left behind excellent stuff never burns off I don't know if you can buy it here anywhere around here.
Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker.

yes you can use fancy silicone RTV , however the cheap bathroom stuff just as well.

you do not need to leave it overnight as it sets within 10 mins.

slap it on nice and thick , wipe surplus off with a damp cloth

I just had this same problem last week. I used the "fancy" Permatex Ultra Copper, as the bathroom caulk suggestion scared me a bit...I didn't think it would hold up to the heat? I guess it does, as it seems to be recommended by many. The Permatex isn't too expensive, about $7 USD for a small tube (which is re-usable and has many other gasket uses)...vs. $5 for a full tube of silicone caulk, which ends up getting thrown out due to drying out after some time. I also added the finned cooling ring at the same time, which also hides the orange bead of Permatex. Good Luck! Tim

Thanks to the advice here I have resetted my wobbling exhaust pipe with bathroom sealant - much against the advice of my local mechanic. LOL