Ignition timing advancement/retardation

[Motu]

What thread on ADV?

[CookMySock]

It's only worth fiddling with your mixture and advance curve if you have a specific reason to, such as converting a touring engine to race use, or building an engine up from scratch. Mostly you will see the former - removing the lean-run lower part of the rev range for maximum off the mark performance, removing the now-useless rev-limiter since you have race cams and exhaust etc.

Steve

[slowpoke]

I fitted a 4deg advancer (simple plate) to my carb'd R1 and there was a noticeable improvement in throttle response, especially through the mid range. It wasn't a night and day improvement but it definitely felt crisper on the pants-o-meter. This was after a comprehensive mod/rebuild that included raising the compression so it's obvious that M/C manufacturers tune their bikes fairly conservatively to cater for the crap fuel found throughout the world. It ran fine on just Premium Unleaded (no 98 in town). I had the bike dyno tuned after the rebuild but have no dyno results from beforehand so can't give quantitative results for the advancer alone. Suffice to say it made identical max power to a K5/6 gixxer thou' (with PC111 and can) on Welly M/C dyno at 1000rpm lower, not too bad for an old school bike.

From the admittedly limited reading I've done higher octane fuels are denser and burn slower (hence reducing prospect of detonation) and engines will actually make more power on the lowest octane fuel that avoids detonation. (98 will give a slower longer bang while 96 (for example) gives a shorter sharper bang) Running your standard bike on 98 may have a feel good factor but it will actually make more power on 96.

[t3mp0r4ry nzr]

good info, but how is it done? rotating clockwise will advance, counter clockwise retard?