High idle on old 500 classic, any thoughts

[BRULEDRIFTER]

I just pulled my old sleds out of storage to sell, they were stored for 2 plus years. Both start fine but I have a '89 Indy 500 classic that starts and then idles up to about 3000RPM and continues to do so. Any ideas to throw out?

[trackerbrent]

Good sleds, very easy to work on. My 1st thought after sitting two years in stuck slide or throttle cable. Check the throttle cable 1st, then rip in to the carbs. Take apart everything in the carbs. Check the needles, on the needle and seat, to see if the spring still works freely. Other than that, clean and inspect carbs is all I can suggest. Thoroughly soak and blow out ports and jets with air gun. 90% of the time with these Polaris's, it is the carbs that are causing the engine problem. Good luck and I may not be right here, just throwing it out there.

[MNRookie78]

On that age of a sled I would also think about a dry crank seal leaking air. It's easy to check the clutch side seal. Start it up and spray some carb clean behind the clutch. If the RPM is affected the seal is leaking. If no change then I agree...go into the carbs and see if there is something plugging the jets causing it to go lean on fuel.

[hanson]

After 2 years of storage, you probably just have to thoroughly clean the carbs. If it still idles high, adjust the idle down on the carbs.

A crank seal is more than likely going to cause other problems as well. Its a potential problem but you really want to eliminate the easier fixes first.

[Gissert]

It could also be a cracked or leaky carb boot too.

I'd get the cause of the high idle nailed down - air leaks are good way for your engine to meet the dreaded Mr. Squeaky.

[CalderPointCabin]

remove both carbs and make sure the pilot and main jets are clear. make sure the float needle is not sticking.

get rid of all the 2 year old gas thats in the tank and refill with fresh stuff. see if that does anything to help.

as stated already, an air leak will grenade the motor your first ride out.

was the fuel stabilized when the sled was stored 2 years ago?

[BRULEDRIFTER]

Yes, the fuel was stabilized. Carbs were fogged.

[Reynolds]

I started my sled up on Friday night and had the same situation that you have described. I ended up pulling off the carbs and giving them a thorough cleaning and then synchronizing them as well. The culprit turned out to be that the main jets were clogged from sitting over the summer. If you are not familiar with cleaning carbs you can find step by step info on the internet on how to go about cleaning your specific brand of carburetors. Shouldn't take you much more than an hour or two to clean and sync.

[BRULEDRIFTER]

OK guys, I pulled and cleaned the carbs and still has the high idle. Also sprayed some carb cleaner behind the clutch and it didn't change the idle at all. Any other "easy" checks before I bite the bullet and bring it in?

[mudslinger64]

how many turns out do you have your air mixture screw?turn it out 1 turn and adjust from there,turning it in will richen it up and out leans it,sounds like it is turned out to far to me.this is the small screw on the side of the carb by the air horn not the big one on the side that adjusts the slide up and down.

[BRULEDRIFTER]

Both are 1 turn out....That is what they were when I pulled the carbs and what the specs say they should be. Should I turn them in a bit and see what happens?

[mudslinger64]

yes 1 turn out is just a starting point.i am pretty sure on my 900 triple i have them around 3/4 of a turn out every sled is different.turn them in a little and blip the throttle and see if the idle comes back down.also are you sure you have the carbs syncronized right?your slide may not be adjusted right when you hold the throttle wide open does the slide go up past the bore of the carb?it should be even with the top of the bore if not adjust the cable so it is.take an 1/8"drill bit and adjust your idle screw so the bit slides under it with a little drag if you have dual carbs make sure they are both the same after the sled warms up you may have to play with the idle screws a little to get it to idle around 1500 rpm.

[Reynolds]

I should rephrase what I said in my earlier post. I was having trouble getting my sled started, so I cleaned the carbs only to have it idle at 3000rpm. The reason it would not start was due to the clogged main jets. After adjusting the idle screws to no avail, I synchronized the carbs and that cured the high idle. I personally used a 3/16'' drill bit for setting the idle and ended up about 1200rpm. I then adjusted the idle screws from there to bump up the idle. By the way, I have 34mm Roundslide Mikuni carburetors, which I believe may be the same carbs you have.

[BRULEDRIFTER]

Thanks guys,

Pulled them again and cleaned them again. I noticed that one of the cables was a little tight when I pulled the airbox and wonder if it just wasn't hanging up the whole time and I missed it??

It's running great now though!