Quote:
Originally posted by bwamos
For optimal performance... yes you'll have to rejet ANY quad when humidity/temperature changes a significant amount.
There's a LOT more O2 in the air when it's 2 deg F w/ 0% humidity, than at 95 deg F @ 35% humidity.
You don't "have to" but you should, and you should even be adjusting the mapping on the EFI models. You aren't running a self-adjusting EFI Controller w/ an sensor in the exhaust.
If you're not running lean at 5 degrees.. you were running WAY too rich at 95 degrees.
Great post bwamos! It is definitely your choice to rejet or not but it is much better for your engine if you do. Pretty sure I saw somewhere that for every 20 degree drop, it constitutes a jet change, larger or smaller depending on temps rising or falling. It is the same principle as riding at seal level and at 5000ft in the mountains. The higher you go, the less O2 in the air, which means you should go to a smaller jet size, and vise versa.