Running lean

[sleepy]

4.6 is a bit to much. What size carb and main jet have you got, I have seen carb come jetted and be miles out.

[Lozza]

Ok thanks for the help , I don't know who is more retarded me or the bike . I had set timing at 2.1 btc on assembly on checking with a strobe light almost 4.6 btc . I knew the head and jetting would be very close due to using a DT1M head and cylinder ported to DT1M specs, the carb was new from Hatricks jetted to DT1M specs . pipe built by Peter Worrel . Thanks again gents , Iain

Is 4.6mm the static timing at idle or is it fixed/straight line through the rev range? At what throttle  position is the plug white?  I'd agree 4.6mm is unnecessary. Have you done a leak down test? Unleaded fuel?

[Iain Cameron]

fixed through the range Lozza . the plug is white at anything over idle . no to the leak test but used soapy water over all seals and inlet manifold joints .

[Lozza]

I calculated that nearly 28deg  of advance (64mm stroke 125mm rod length) 2.65 is 21deg which sounds more reasonable

[sleepy]

fixed through the range Lozza . the plug is white at anything over idle . no to the leak test but used soapy water over all seals and inlet manifold joints .

Is the white a deposit colour or just a clean plug? The stock timing for a DT1 is 3.2mm and from memory when the kit head was fitted it came back to 2.8mm. Have you checked the seal on the primary drive side, the white deposit could be gearbox oil getting in.