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Discussion Starter #1
I asked this ? before, I need to try again. I have a 97 Ultra SP. It has SLP pipes, V Force reeds. When I first start it for the day, If I don't keep the rpm's up around 2k it will foul a plug, not necessary the same one all the time. After it has warmed up, I can let it idle. Even after a stop for lunch or something. I put a new set of needle and seats in it yesterday, same thing. Any idea's? Thanks,

Runner
 

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how low is your idle set at? on my zrt it will idle at around 3500 when i first start it then it will drop to around 1800-2000 when warm,sounds like your idle is set too low
 

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bardillo is onto something there. when it is cold on a warm up stand. does it want to idle up then come down when it is warm?

maybe that when it is cold the cylinders just cant burn the amount of fuel at low idle. nothing might be mechanically wrong. just set the idle up a little when it is warm, when it is cold stand there and move the rpm up and down on the stand, you should be doing that anyhow to loosen the belt and track and get the engine good and warm so you dont score it.
 

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Runner your idle is supposed to be 1800 +- 200 RPM. Mine is set at 2000. It starts up on the second pull and I just give it enough choke to keep it running. Once it Idles good (usually around 3000 when it's cold) I put my gear on and it's good to go. You may need to adjust the pilot air screws.
 

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Personally i would have the carbs sync'ed....this would be my first step in the process to possibly get the cold idle to work properly.
 

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you sure you have the right heat index plugs in there?

also, try leaning up your idle... It should rev up some and almost try to die when cold... Then it should kinda idle down a little as it warms up (a cold engine runs leaner)

-Dean
 

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Discussion Starter #7
The idle was set at 1100 when it is warm. I guess I'll bump it up some, and try that. I definitely run the track around and warm things up before I ride. I have NGK br9es plugs in it. I'm not sure on how to sync the carbs. I have set the carbs before and they are set up the same. Thanks guy's,

Runner
 

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I think it is obviously to rich. Did you put the pipes on yourself? if so, did you use SLP's recomended jetting? What size pilot jets, and what is the air screw setting that you are using?
 

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Discussion Starter #10
I worked for a winter sidelining at our Polaris shop, The top mechanic and I put it together. I had Dyno ports on before (too loud)But had no problems at all. I switched to SLP's and this problem. We did switch out pilot jets. I can't remember what they are, but, I know they were as low as he dared to go. It has always had a slight bog at the begining, can't seem to get rid of that. I might have to play with the air screws some.

Runner
 

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TOO RICH!!!

classic signs of too rich at idle.

Bog, fouling plugs at idle, and low idle RPM when cold.

Your idle should be set when the sled is WARM. When the sled is cold, due to the motor being cold, it will run leaner, and automatically idle up some, as I explained earlier... If you set your idle cold, then once your sled warms up, it will either idle wayyy too fast, or will kill (depending on if your rich, or lean at a normal cold idle).

-Dean
 

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Discussion Starter #12
All of our snow is melting. I'm not sure when I'll be able to get it back out, warm it up real good and bump up the idle. I'll set it at 2000 rpm's when it's warm, does that sound good? Thanks for your advice guy's, I'll post an update as soon as we get more snow.

Runner
 
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