I know its been talked about a lot.... But I cant find much so, what should I be looking at for my afr on idle? Around 15?
What target idle AFR
- Thread starter RobertTrivanovic
- Start date
Yes 15:1 at idle is good.
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inspector01
Well-known member
Generally stoich (1 lambda, 14.7:1 for gas) is desired for idle, but a bit leaner is fine.
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izzni
Well-known member
Leaner is better at idle for fuel efficiency and perhaps avoiding fouled plugs. 14.7 AFR is the most efefficent ratio.
That ratio however provides inadequate fuel for developing the most power out of an engine, amd more importantly, it also provides inadequate cooling on a two stroke at anything but very light throttle positions.
So although 14.7 is idle for efficiency at idle, I would suggest basing what ratio you aim for on throttle responss. If you can hammer the throttle and it goes great at 12 AFR during idle, but falls on its face if you idle it at 14.7, keep it at 12 and don't worry unless you foul plugs.
My M1100T idles at about 12AFR for what it is worth. Only time it bounces around 14.7 is during very lglight throttle.
That ratio however provides inadequate fuel for developing the most power out of an engine, amd more importantly, it also provides inadequate cooling on a two stroke at anything but very light throttle positions.
So although 14.7 is idle for efficiency at idle, I would suggest basing what ratio you aim for on throttle responss. If you can hammer the throttle and it goes great at 12 AFR during idle, but falls on its face if you idle it at 14.7, keep it at 12 and don't worry unless you foul plugs.
My M1100T idles at about 12AFR for what it is worth. Only time it bounces around 14.7 is during very lglight throttle.
