Does anybody know how far to advance the timing on the 670 motor? I know if you go to far you can fry it. I had it advanced on my 583, but i wasnt the one who did it and i dont know how far it was either.

If your gonna trail ride it dont even think about it, the 670 is edgy enough already, if your gonna just 500` it I can look up the specs but its measured in piston travel. Looking at it with a timing light however it really only looks like 3 degrees or so or the high side of the first slash mark, but again if your gonna trail ride it dont dooit.

STock us .076 btdc ..racebook says you can go +.010...Irun mineat .082 and 155 psi. compresion...so a stock head should permit even more advance...IMO