Timing plug colour

[jonno]

Can the timing affect plug colour? Im trying to set up my mugello 225 with 30mm delly Jl3 pipe but getting nowhere even with the settings I had previously.Had a holed piston a while back so a complete top end stripdown.Marked the stator and replaced at the mark.Have agusto fitted,checked timing with mark moving towards the previous marks set on flywheel. If this was out could it affect the plug colour,as im rich to half throttle lean above.

[byron]

yes.
too advanced it will run hot, indicated by the plug colour
"...the previous marks set on flywheel..." ~ if you don't know these to be right, find TDC and make your own marks

[Adam_Winstone]

^... as stated above. Yes, timing has as much influence on plug colour as jetting, the two go hand in hand and neither should be considered in isolation.

If the previous marks resulted in a holed piston, you certainly don't want to trust them again. Find TDC again and determine what your final max retard figure wants to be, then mark a range from too little to more than your maximum advance will be, then strobe it and watch the arrow move across the range, then adjust the stator accordingly. Depending on your motor's specific setup and requirements, you'll need to mark the flywheel or mag to show a range of something like 28-12 degrees, then you can set it to something like 24-16.

Best of luck.

Adam

[CHRIS in MARGATE]

I always recheck TDC. Assumption as they say is the mother of all evils. That is the first task before going any further. Make a positive stop out of an old spark plug and after you are 100% confident scribe a new TDC mark.
If after retiming, this fails to change plug colour then drop the clip on the needle to a lower slot and go from there.