High Idle [Archive] - Snowmobile World : Your #1 Snowmobile Forum

: High Idle

12-15-2002, 11:48 PM
The sled is a 96 xcr 600 sp that my father picked up blown up with 1500 miles on it for almost nothing. The problem is that is idles at about 4000 rpms and wont come down unless you choke it, but it well slowly climb back up. I know the guy he bought the sled from and it has always been this way. I know this sled came with a ton of problems from the factory but I cant seem to find all of the polaris updates anywhere on the internet. I dont think many if any of the updates have been done to it. I was wondering if anyone knows were I can find these updates and if anyone has any carburation tips for this sled to get the idle back down to normal.

12-16-2002, 01:14 AM
First thing to check is your rubber carb boots for cracks. Air leaks will cause the condition you are experiencing. Next, remove air box and check the slides to see if they are synchronized, when throttle is at idle position, use 3/8 drill bit to measure slide clearance. Slides should just touch the bit. Try spraying carb cleaner toward the engine behind the primary clutch, if engine speed changes, you probably have a seal leaking. Try these 3 things, if you do not find the problem, post here again and we will try something else.


12-16-2002, 05:31 PM
This spring when I rebuilt the motor the crankshaft was replaced because of a bad bearing by a local engine shop, this is why it was blown up. They put in a new crankshaft with new seals and I finished putting the rest of the motor together. I syncronized the carbs and checked the carb boots when I rebuilt the motor so I know that is none of the things you mentioned. The carbs are all stock, so I was wondering if anyone knows what mains, pilots, needle etc... to run that will make this thing run better. I guess Im trying to avoid a lot of expermentation. :) Thanks.

12-16-2002, 10:05 PM

Good sled you have there!

I've done several years of testing on these 3X3 to know that that motor can put out serious hp!!

Unstead of repeating myself on xcr set-ups, I have found a good link that can help you get the most out of your sled!


I have run these sleds for long enough to know that this guy's set-up is pretty good - except I don't agree with some of his choices of parts.

First off, I have tried this set-up (actually, I think it's based on an article from snowtech 1996)

Don't use the carbon tech reeds with the Frett brother spacers. I mean it works, but you will be much hapier with the boyesen reeds with stock boots. (cheaper, runs crisper, and makes it easier to remove the airbox)

I don't think you want to simply "geardown" on top. Next years XCR's came with better gearing, but still not perfect. I like to use a 22 top and a 40 bottom (good for 1000' runs). Gets the ratio to 1.81. I also like to keep a 23 top handy for 2000' runs

You can use the clutching in the link, or just keep the stock 97/98 setup. I use a round wire Polaris almond with 54 grams weight. This set-up is best used on the 23/40 ratio, but it's pretty close for the 22/40. These motors run good at 7800-8300 RPM.

You will need to get a CDI from a 97/98 - trust me, best money ever spent. Run 29 deg BTDC with 97/98 cdi. Box will auto-shift you to 13 BTDC at 6000 RPM

Last but not least, TEMPA FLOW II. Most important performance mod for this sled.

jetting for me is 45 pilots, (air screw 2-3/4 turns)
Stock needle from a 97/98
Stock needle jet from a 97/98
Keep the jetting 340-360-360 with the tempa flow

I run a DG triple pack silencer on mine - throttle responce is incredible.
BUT i keep 360-380-380 mains with the tempa flow on this set-up.

Keep the front shock tight. get as much power to the ground as you can. If you find it pushes too much in corners pull in your limiter straps.

KEEP THE CARBS SYNC'd. and belt deflection right on. These motors don't really like to be run under 4600 RPM.

Don't get bent up on the idle drop after an extended stop, it's built like that... Timing retards to throw more heat into the pipe and lowers engine stress. If you want more details on that perticular subject email me.

Good luck!

12-17-2002, 10:30 PM
I WOULDNT worry about the hight idle. theres pretty much nothing you can do about except turn the idle speed down. both my 00 and 01 600 xc's did the same thing. you just got lucky like i did.

12-18-2002, 09:45 PM
Thanks for the information guys.

Its finally snowing here in Minnestota!!
It'll be nice to put some miles on for once.

01-04-2003, 01:35 PM
my 96xcr600sp does the same thing.

How did you bleed the colling sys on yours after bleeding cooling sys?

Do yourside coolers get warm if you let it idle for 5-10 minutes?

Mine are cool yet upper hose is hot and cooler under seat is luke warm.
I'm concerened I have cooling problems.
Thought you had same model maybe this is normal?

01-05-2003, 08:26 PM

When I rebuilt the motor I spent alot of time bleeding the system. So Im pretty sure I got all of the air out. My father has put about 350 miles on it since the rebuild with no problems except the rather high idle, plus I checked it today when we went riding and I didint see any air come out of the system.

When I initally bled the system I picked the front end up slightly and ran the moter with the radiator cap off for a couple of minutes . I did this several times, and I believe this is the only way of bleeding the system. I've done a few sleds this way and have never had any problems doing it this way.
I've never checked on how warm the heat exchangers ever got though. :)