Scrambler starts without using choke (cold) and I think I'm looking at a "wet fouled" spark plug according to the manual..... manual also states variation to the carb air screw 1/2 to 1 turn clockwise for improved cold weather starts and 2 turns counterclockwise for hot weather and or high altitude. I also noticed the spark arrestor has wet black oil at the tail pipe and it does smoke some. Other then that it runs well but I'm afraid to make any adjustments without asking for opinions. Also should I start by turning air screw all the way in or adjust from its set position ?

THX

 

How long since you've replaced the needle and seat and checked the float level? Sounds like too much fuel. Especially cranking up in cold weather without having to use the choke.

 

I never replaced those items

thx

 

Might be a good time to rebuild the carb.Needle and seat are probably worn and allowing to much fuel into the engine.Cheaper to get a good quality kit than just an oem needle and seat.Shindy ATV Carburetor Carb Repair Kit Polaris Scrambler 400 03-0406 Here's a couple good videos on this style carb.

 

ok....thx OPT ill give it a try......after I do the rebuild how many turns do I turn out the Air screw ?

 

Before you take the air screw out,count the number of turns in until it's lightly seated. Usually you'll end up at 1.5-2 turns. You can fine tune the air screw when the engine is warm. Turning the air screw in slows down air and makes for a richer mixture at an idle. Turning the screw out allows for more air and a leaner idle mixture. Most times 2 turns out is sufficient and it will take throttle without bogging or hesitation. Remember the air box and filter have to be installed to adjust the mixture properly.

 

will do.......and thx again