I just started using 91 octane in my blaster and the performance outcome is noticeable but when i pull in the clutch or let off the gas while i'm going...it idles high and then slowly goes down. Is this because of the gas or the cold weather. If I adjust my idle would that fix my problem?

 

Sounds like it may be running lean. When 2 strokes are running lean, or out of gas they idle higher. My lt winds right out when it's running out of gas.

 

could it be running lean because the sudden drop in temperature?

 

That should actually make it richer. It could also be a mechanical thing, like the slide in the carb not returning quick enough.

 

doesn't a higher octane gas burn slower or something like that? and the motor wouldn't burn it fast enough so it takes a while to go back to normal idle speed

 

not that i know of.. thats what ppl think when gasing the cars up, thinking it takes longer to burn and they would save moeny on gas.. but its false.

 

Huh? Colder air is more dense leaning the air fuel mixture.

 

I always reverse that for temp and elevation.[img]i/expressions/face-icon-small-blush.gif[/img]

Anyways, I live in New England and we have some pretty drastic temp changes. Highs sometimes over 100 and lows well below 0. I was actually working outside a couple years ago and it was -21 and 40 below with windchill. I've never noticed a real big difference and have never felt the need to re-jet. I think it may be different on a highly modded motor. My point is, I don't think it's the temp change causing your issues.

 

i'd say it's lean from the colder weather if it only started acting up when the weather changed. Colder weather makes the neighbor's 125 dirtbike act up like that too.

 

my bet is your slide is hanging up due to the cold weather, or you have a dry throttle cable also aggravated by the cold weather. lubricate both and then see what happens. I'll guess the problem will go away. You shouldnt suddenly have a problem with rich/lean just because you changed octanes. It's gotta be lubrcation/weather related.
take the throttle cable off at the bars and tape it to a broomstick so it's vertical. then shoot some light lube down the cable and let it sit.
then you can unscrew the carb top and pull the slide. clean it well and lube it LIGHTLY with some light lubricant.
unless youve been into the jetting or torn the engine apart, this should solve your problem.
let me know if I can help you.