not wanting to idle down?

[Tyler23]

i got a 03 600ho rev, and when its at opperating temp. it has a tendecy to not want to idle down. it kinda just stays up there around 3400. i've heard this is a common problem with ski-doo, any idea what to try first?

[dan z]

flip the choke lever up till it coughs and then it should settle down I'm no mechanic but I do this sometimes to cool down the idle on other sleds I have used...

[311Hemi]

Fairly common problem with the 600ho's.

Has your sled always done this? If you blip the choke will it idle down and stay down?

There are a number of things to do/check. If it's idling high the engine is lean. If your sled has not always done this the first things I would check would be the carb boots. It is a VERY common problem that the carb boots crack or delaminate and thus let air in....causing a lean condition (and blowing the engine..BAD). You will need to pull the carb boots off the sled/engine to inspect them (bending them in your hand, looking for bubble in the rubber, etc.) You can't see that while installed.

If the carb boots are good, and you have cleaned the carbs you could try adjusting the fuel mixture screw 1/4 turn out (make the idle circuit richer).

Start with the things above....but one other thing that may be worth checking (probably not your issue but still a small chance) is pulling the primary clutch off and inspecting the PTO shaft seal. Make sure the seal is flush with the engine block and there is not a bunch of grease around the shaft. This can also cause a lean condition as once that seal goes air come in through that location. That is BAD.

Edit: The PTO shaft seal would not let air into the engine, but it would cause the loss of isoflex (grease) which also lubricates the internal shaft bearing....and if that internal bearing goes then you could pull air (or grease) into the engine. That is not good!

[Tyler23]

thanks 311hemi!! i turned the screw out 1/2 a turn and it idles wayyy better now. i was afraid i had a air leak in the engine, i really didnt want to deal with that.

[311Hemi]

Glad that worked for ya. Keep in mind once you get into warmer weather you may need to adjust it back a little. I don't know how much the cold temp will affect it, but I would venture to guess some. It would just be richer as it warms up.....but I'm not sure if it would foul your plugs or not.

Also, if you have not done so I would strongly recommend pulling your carb boots and inspecting them. I have heard of a number of Rev engines going down because of bad boots. The 03' 600ho I had two years ago had bad boots, they were delaminating and bubbling and I could have burned the engine down at any time (I am glad I took the time to inspect them). I bought a set of RAD valves for the sled and never looked back.

[Hard617]

I dont think you should turn your idle screw out and leave it. You have a lean issue somewhere and the "bandaid" you just put on it will seize it up. There is definately an issue there and you need to find it. Also, 311Hemi mentioned the pto seal. It could very well be that this seal is bad. The '03 rev's also had an issue with this and either in 04 or 05, they put a seal retainer in. You can get this retainer from your dealer, and I would highly reccomend that you do it. A blown belt with cord wrapped around your pto shaft will tear that seal up. But first, find your lean issue.

[Tyler23]

well before i had adjusted the air screw it would pop every once in awhile and after adjusting the pilot screw it runs like a champ and no more back firing. one of the boots was replaced last year and the owner that had it before had one cylinder replaced because that one got to lean. but the mechanic said the other boot is good. it doesn't leak any fluid and i dont know where else there could be air getting in. but it runs good now and i put about 70 miles on it tonight without any problems

[311Hemi]

If the carbs were taken apart at some point and cleaned then fuel screws (white plastic screw on each carb, not the idle adjustment screw) might not be adjusted correctly and could cause a leaner idling thus the higher RPM's (would be the first easiest thing to check). You can check what they are set to if you want to...the stock setting if I remember correctly is lightly seated and backed out 1.5 turns. You can finely tune from there if needed (I know I had to run mine around 1.75 turns out from seated). The idle adjust screw would also need to be set properly for it to idle correctly...so it's possible that adjustment was off a little.

Good thing the boots were checked....as the previous owner experienced what can happen. As hard617 mentioned and I would second his suggestion.....install the PTO seal retainer. That's why I said to check it first to see if it was popping out at all. When I had my 03' my seal was out about 1/16-1/8 of an inch but luckily not far enough to lose any of the isoflex(grease). I tapped it back in and installed the seal retailer. My buddy just did his last month...his seal was also popping out a little but had not gotten far enough to leak. Cheap security...and as mentioned especially if you blow a belt. If this seal has gone out you will see a grease built up around the seal/shaft, and it will probably be all over the back of the primary.

[Tyler23]

well last year after i bought it i had a guy go threw it and he went threw the carbs so it prolly didnt get turned right. he was kinda in a rush at the time with other sleds so it prolly just didnt get turned right. it runs great now, no backfiring.

[Tyler23]

do you guys think i should look into my sled further or run it untill it idles weird again?

[311Hemi]

Well, a sled idling high is not uncommon. If carbs are not adjusted properly this can and will happen....more so on the 600ho's in my experience. Now if it was fine all last year and now this year it is acting different....then you may want to check things out a little more. If the carbs were just cleaned or redone recently then most likely they were not dialed in just right when put back togeather and they needed to be adjusted a little.

First things first would be making sure the carbs are clean. Next, if you are sure the carb boots are good, then that is one major area of concern that would be ruled out. The next major area would be to inspect the PTO seal behind the primary to see if there is any grease there (it would be noticeable)....although there is a less of a chance that the pto seal is bad it should be checked to rule out.

One other thing you could do is check your jetting at idle, mid range, and wide open throttle to see if your getting any lean conditions which could also help show if you have an issue. Get the sled good and warmed up and then let it idle for a min or two and shut it down. Pull the plugs and see if they are white (lean), card board brown (good), or black (rich). Next, run across a lake at 1/2 throttle for at least 1/2 mile then shut down the engine keeping the throttle exactly at 1/2 throttle until the engine is off. Check the plugs again. Last, do a run at wide open throttle for at least 1/2 mile and shut down the engine with the throttle pinned until the engine is off. Check the plugs again. This will give you a general idea of how your engine is running at these ranges. You really don't want white plugs any time.

If I recall correctly the jetting is the pilot circuit from 0-1/4 throttle, the needles from 1/4-3/4 throttle, and the main jet from 3/4-WOT.

[Tyler23]

well the boot was ripped when i bought it so idk what it ran like when it wasnt ripped. but right after i got it i had it gone threw and the carb were taking off and gone threw. and right after i got it back it ran like that so my guess is it wasnt tuned. i checked the boots today and there good, there is no grease leaking out behind the primary. i will check the plugs like you said the reply