My 2-stroke tuning experience has all been with a T-Maxx nitro r/c car. With a nitro car the more lean you are the more power you have and the more heat you have. As it gets colder, will a 400 scram have more power with the more lean mix? Will it run lean enough to overheat in the cold? Do we have to re-jet larger? I may ride 2-3 times below 40 der. It seems like a pain in the a$$ to re-jet for just a few times out untill next spring when it warms back up. Any help would be great!

 

when i had my stock 400 i never re-jetted and i ran in below 25 degrees. alot.

 

Just don't want to burn out the piston. First owner got it in April and traded in Oct. It sat at the dealer untill June when I got it. This is the first winter it will be ridden.

 

Best quick thing to do is just unscrew the carb top and move the needle up a position or basically move the clip down one notch. Part throttle tends to be a lean spot on those carbs and that will help cure it. I have to rejet a full main size and move the needle a notch to keep my wife's scrammy from cold seizing in the cold air. Might be different for us, but our summers get close to 100 and the winters get to the teens. That's a big gap that you cant fill with one setting. Also make sure you give it twice as much warm up time in the winter months. Bubba

 

Move the clip a notch, I will get out the service manual to locate what you are talking about. Is this a factory recommended adjustment, or will it not refer to this clip as adjustable? Thanks for the tip!

 

Most of the polaris 2 strokes are jetted rich from factory so you should not have to rejet for the cold. Tha main thing is DO NOT run full open throttle for long periods or you will burn up the piston. Otherwise dont worry.