[Idle/Jetting help needed] - ATV Riders Forums - Honda, Yamaha, Suzuki, Kawasaki, Polaris, CanAm, Arctic Cat, Kymco ATVs

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Idle/Jetting help needed
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Posted by: 250r rider 88

OK im still having problems with my r running right here are the mods

Stock carb with 160 main jet and clip on 3rd postion
ESR TRX 6 pipe and silencer
K&N filter
air box lid off

i think i have the right jet at 160 cause when i ride it it doesn't miss and flat out hauls, runs great but as sson as i stop it will die if i dont keep reving it and the nsometimes it will idle and sometimes it wont ive tried turning the idle up to see if it would "catch up" but i just doen't like sitting there running

any advice???

Posted by: 250r rider 88

alsoi run klotz supertechniplate 3 ounces to a gallon of 93-94 octane if that helps

Posted by: YFZRob

What is your air screw set at? Also what pilot jet are you running. Too rich on the pilot or improperly adjusted air screw will cause difficulty idling. The needle and main jet that you mentioned have virtually zero affect on idle.

Posted by: 250r rider 88

air screw at 1 7/8 turns out stock is 2 i believe and the pilot is a 48

Posted by: 250r rider 88

could it possibly be bad gas because i used sunoco this time istead of circle k and i m wondering if that can make alot of difference?

Posted by: YFZRob

Try running a 45 pilot and open up the air screw to 2.25 or 2.5. The 48 pilot is too big for a stock jug w/ only a pipe. My 2005 RM250 runs a 48 pilot stock and I'm down to a 45 in that!

Or ditch the POS PJ stock carb and get a Keihin PWK 36 or PWK 38 Air Stryker. They will give you a nice HP gain and be much easier to set up correctly.

Posted by: 250r rider 88

ok ill get a 45 in there also ive heard that a two stroke wont just sit there and idle no matter how good its setup is this true casue it owuld idle before but now when i stop to rest or something it wants to die and do u think i could be bad gas

Posted by: YFZRob

If the gas isn't old, meaning you didn't sit on it for 6+ months, then it's not an issue. You rarely get bad gas from the pump anymore, at least here in FL. And bad gas usually has no issues with idling, only with making good power under engine load.

2 strokes will idle all day long when properly set up. Anyone who says differently doesn't know what they are doing. When I go riding, I fire up either one of my 2 strokes and let it idle for at least 5 minutes straight after turing off the choke. They never stall and both idle right around 1200 RPM.

Posted by: wilkin250r

2-strokes are more likely to foul plugs if you let them idle for too long, but "more likely" doesn't translate into "definitely". I can let mine idle for 20 minutes without fouling plugs

Posted by: dynofox

You've tried the idle adjustment right?

Posted by: xlr810

Did it ever idle properly? Specifically-- did it work fine prior to this tank of gas?

Turning up the idle on the stock PJ carb is closely related to pulling the chock knob-- same circuit. Sounds like you are rich at the slow speed circuit. First determine if it is the gas. Make sure your final jetting is done on a warmed up engine.

Posted by: xlr810

Here in the north (compared to FL) they change the composition of the pump gas seasonally. A little fine tuning between fillups is not unusual for me.