The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: brissy_bsa on 21.04. 2010 12:34

Title: EXHAUST ISSUES 51 Plunger A10
Post by: brissy_bsa on 21.04. 2010 12:34
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
Title: Re: EXHAUST ISSUES 51 Plunger A10
Post by: RichardL on 21.04. 2010 17:03
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.
Title: Re: EXHAUST ISSUES 51 Plunger A10
Post by: muskrat on 21.04. 2010 20:16
G'day Ian,
              sounds like valve guide to me. Did you replace them in the overhaul ?
Cheers
Title: Re: EXHAUST ISSUES 51 Plunger A10
Post by: brissy_bsa on 21.04. 2010 22:52
Yes, new value guides were fitted. May have to investigate further. Thanks
Title: Re: EXHAUST ISSUES 51 Plunger A10
Post by: muskrat on 22.04. 2010 12:42
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