Who knows, 100% certain, how much the stock igniton system can adjust timeing? The service manual I have is a bit confusing but it sounds like it can adjust timeing from roughly 10 degrees ATDC to about 20 degrees BTDC. The base is 5 BTDC +/- 3 and the manual says it is varible (self adjusting?) by about +/- 7 and an additional 5 BTDC from 15 BTDC. Makeing it 20 BTDC. The wording is confusing to me. Am I getting this right? Does anyone know of an after market igniton that can retard/advance timeing more than this?