Picked up a 2000 Polaris 120 for my son this weekend. It has the Recmotor's adjustable main jet on it. I was wondering how this actually works? I was trying to turn aluminum knob but it ended up twisting off of the long spring. Is this long spring supposed to turn the jet? If so could it be possible it's froze up at the bottom of the bowl. I also noticed the plug is very carboned up. Even after cleaning it and running the engine briefly the spark plug was completely black again. Any help pointing me in the right direction would be greatly appreciated. Thanks!
Polaris 120 Adjustable Main Jet
- Thread starter cyleblohm
- Start date
Been fighting with mine since last year. Previous owner rode it hard and put it away wet so to speak. Instructions off the RecMotor site say ...
(REMOVE NEEDLE FROM BRASS ADJUSTABLE MAIN JET & INSTALL BRASS BODY IN FLOAT BOWL IN PLACE OF OEM FLOAT BOWL NUT. RE-INSTALL NEEDLE AND TURN IN UNTIL LIGHTLY SEATED, THEN BACK 1 1/2 TURNS.)
(CARB TUNING PROCEDURE, RAISE REAR OF SLED & SUPPORT SAFELY, HOLD THROTTLE
WIDE OPEN, TURN MAIN JET NEEDLE IN UNTIL ENGINE STARTS, TO DIE THEN BACK MAIN JET NEEDLE OUT UNTIL ENGINE RUNS SMOOTH AT THIS POINT TURN NEEDLE OUT 1/4 TURN MORE)
This worked great for me. After cleaning the carb good and getting some other little things figured out the sled is a ripper now. I think I definitely need to replace all the gaskets. Still trying to get it to idle at a lower RPM without dying off. Wish I knew more about carbs myself to get it where we need it.
(REMOVE NEEDLE FROM BRASS ADJUSTABLE MAIN JET & INSTALL BRASS BODY IN FLOAT BOWL IN PLACE OF OEM FLOAT BOWL NUT. RE-INSTALL NEEDLE AND TURN IN UNTIL LIGHTLY SEATED, THEN BACK 1 1/2 TURNS.)
(CARB TUNING PROCEDURE, RAISE REAR OF SLED & SUPPORT SAFELY, HOLD THROTTLE
WIDE OPEN, TURN MAIN JET NEEDLE IN UNTIL ENGINE STARTS, TO DIE THEN BACK MAIN JET NEEDLE OUT UNTIL ENGINE RUNS SMOOTH AT THIS POINT TURN NEEDLE OUT 1/4 TURN MORE)
This worked great for me. After cleaning the carb good and getting some other little things figured out the sled is a ripper now. I think I definitely need to replace all the gaskets. Still trying to get it to idle at a lower RPM without dying off. Wish I knew more about carbs myself to get it where we need it.
Mine almost sounds like it's backfiring when at idle also. But never having on of these little guys I'm not sure what is normal or not. Thanks for the info.
B
built4dtuff
Well-known member
The handle part of the adjust has a set screw you can put it back on the end of the braided cable. Then follow instructions above. Look at bottom of carb to make sure cable is turning the other end. If not it might be seized up so just stick your hand under there and turn it by hand to free it up. When you have it adjusted right the engine will hopefully make a nocking/rattling noise. This is good!! Hard to understand or put in words but if the engine sounds like its falling apart inside she's running good. Adjustments will need to be made as temp and humidity change.
Racer I wouldn't rebuild the motor! The more miles and the looser the engine the better they run! My son raced the stock class for 3 yrs and I can honestly say I'm damn near an expert on those stupid 120's.
The blizzard clutch, quick change hub,and 35 chain are nice upgrades also! You can get those little thing rippen pretty good for a lawn mower engine
Have fun and enjoy! You think it's fun now wait till your digging your kid out of his first tree up Mtn riding and he thinks it's the coolest thing ever!!!
Ps west Yellowstone has races during expo! Pm me if your interested and I will tell you what you need to make the sled competitive. Always lots of little ones at west and its a blast!!!
Racer I wouldn't rebuild the motor! The more miles and the looser the engine the better they run! My son raced the stock class for 3 yrs and I can honestly say I'm damn near an expert on those stupid 120's.
The blizzard clutch, quick change hub,and 35 chain are nice upgrades also! You can get those little thing rippen pretty good for a lawn mower engine
Have fun and enjoy! You think it's fun now wait till your digging your kid out of his first tree up Mtn riding and he thinks it's the coolest thing ever!!!
Ps west Yellowstone has races during expo! Pm me if your interested and I will tell you what you need to make the sled competitive. Always lots of little ones at west and its a blast!!!
