750/650 timing

bormz · 06-07-2009, 07:49 PM

I have a 750 big pin with 650 electrics in my x2 .. I was wondering how much timing advance I can get away with? I want to get what I can out of it but still want it to be reliable. I made a mark on the flywheel at 3mm btdc and put a timing light on it at idle and it lined up, but I was thinking of the advance plate available for the 750 (was that 4degrees?) and wondered if the 750 could handle more advance? Thank you. Craig

Group K · 06-08-2009, 01:59 PM

The amount of advace that can be tolerated is a function of the fuel octane, and the amount of time spent at peak rpm. If you are running pump gas, and often at high rpm....stock timing is all that is safe. More advance will give a bit better acceleration, but much higher temps (and no better peak) in the high rpm range.

Harry Klemm

Quote:

Originally Posted by bormz

I have a 750 big pin with 650 electrics in my x2 .. I was wondering how much timing advance I can get away with? I want to get what I can out of it but still want it to be reliable. I made a mark on the flywheel at 3mm btdc and put a timing light on it at idle and it lined up, but I was thinking of the advance plate available for the 750 (was that 4degrees?) and wondered if the 750 could handle more advance? Thank you. Craig

bormz · 06-08-2009, 02:21 PM

I re checked my timing again and it looks like this.. starts out between my top mark and the fire mark..(3mmbtdc) at idle.... rev up and advances to my 3mm mark, rev to just before the limiter and it heads back to the top mark as if its retarding back at high revs??? I thought it only advanced?

bormz · 06-08-2009, 04:17 PM

I just thought that maybe Im seeing the rev limiter..I dont know how the limiter works.. I assumed that it just grounded the ignition.. but I would swear that my timing is retarding rather than advancing. I would expect to see my top mark moving away, but as it revs I see my top mark getting closer..