EXHAUST ISSUES 51 Plunger A10

[brissy_bsa]

OK guys, tank strap fitted. Now for a new issue. Having just sourced a set of new silencers for the bike, thought I would remove the headers for an inspection. The Left Header was spotless inside however the Right header was coated in a think oily coat of carbon (as in lots of it, approx a 1/8" in places). Considering the engine has done under 100 miles since being fully rebuilt, I am somewhat concerned. Any ideas?  Ian

[RichardL]

If "wet" oily, I would say leaky intake valve guide or head gasket in vicinty of oil passages. Is the plug likewise wet and oily? If you shine a light down the plug hole do you see an oily piston top? I'm guessing that if you run your finger around the inside of the output end of the pipe you will find that to be oily as well.

Richard L.

[muskrat]

G'day Ian,
              sounds like valve guide to me. Did you replace them in the overhaul ?
Cheers

[brissy_bsa]

Yes, new value guides were fitted. May have to investigate further. Thanks

[muskrat]

OK, could the oil drain hole on that side be blocked ? With that much build up in the pipe it must smoke a bit. Next on the list could be a broken oil ring.
cheers