97 Powder Extreme High Idle

[snowfish]

My 97 Powder Extreme (zrt600) likes to idle at 3000rpm. At start up, it will idle around 1200rpm then climb up to 3000. When warm, if I bump the choke, it will come back down but slowly rise back to 3000.

I've checked the usual suspects. Clean carbs, synch, set pilot air, spray carb cleaner on boots and pto seal, cable slack, etc.

Plug color is good. Light to medium cardboard brown.

This model has the Altitude Compensator. Could this possibly be it? Not sure how to bypass the compensator to check.

Any advice, or additional tests, would be appreciated.

 

[robinson]

i had this problem this weekend, normally if you find your idle screw on the engine and rotate it will bring the idle up and down to the proper RPM. Just dont adjust it too much so that when its cold it will have a hard time starting and staying running.

 

[6mile]

When you cleaned the Carbs did you remove the jets and clean the passages? The ones in particular that you need to be conserned with are the pilot jets and the passages. I can't tell you how many times that I have had friends bring over thier sleds and say that they just cleaned the carbs and it still does not run properly. Only to find that the pilot jet is 90% clogged.

I am not saying that you did not clean them properly, but if you have to blip the choke to get the idle to come down, then the first place I would be looking is the pilot circut of each carb. Pull them and be 100% sure they are clean. I have had to re-drill the pilot circutoutlet in the carb body in the past on a couple of sleds because even soaking them in solvent for 24 hours did not loosen the gunk/corrosion.

 

[snowfish]

Starting over at ground zero

Going to go through the carbs again tonight. 6mile reminded me of the 700 Sportsman, that I had to do twice, because I missed some clogged cavities. (that's some surgery! LOL!)

I'm going to try synchronizing them about ½ turn less than baseline idle this time. Can always turn them up if it's too low. Looks like some garage time tonight!

 

[6mile]

It is too bad that our fuel these days is so bad. Used to be able sta.bil the fuel and it would be fine for a year, not any more. Seems after a couple of months it is already turning bad.

 

[bouncer]

My 97 Powder Extreme (zrt600) likes to idle at 3000rpm. At start up, it will idle around 1200rpm then climb up to 3000. When warm, if I bump the choke, it will come back down but slowly rise back to 3000.

I've checked the usual suspects. Clean carbs, synch, set pilot air, spray carb cleaner on boots and pto seal, cable slack, etc.

Plug color is good. Light to medium cardboard brown.

This model has the Altitude Compensator. Could this possibly be it? Not sure how to bypass the compensator to check.

Any advice, or additional tests, would be appreciated.

After you are 100% sure the internals of the carbs are clean, set the pilot screws at 1 1/2 turns out to start. Now warm the engine up to full temp. If you still experience the high idle turn the pilot screws out another 1/2 turn. This will allow more fuel and air to the idle circuit and should stop the high idle hang. This is why the idle drops when you bump the choke, your adding fuel. Good Luck.

 

[snowfish]

ReCleaned the Carbs squeaky clean last night. I went through every frog hair jet and passage 2-3 times. Burned through three cans of carb cleaner. These babies are USDA approved now! Just did this whole drill last fall. Either I missed something, the gas is worse than we think, or a combination of both.

Synchronized, with the slides closed, no idle, all the way at the bottom. Then set everything to spec except for the Idle stops. Those were set at 1 ¼ vs 1 ½. Then fine tune synchronization.

Got it fired up after many pulls to prime the system. Seems I’m on the other end of the spectrum now. Idles at 1000rpms. Sounds like the three bears……..”that idles too high”….”that idles too low”…..now I have to fine the “that idles just right”!

I couldn’t do the final tuning since we (I mean my wife) have a “no motors after 10pm” rule. And it was already 1:30am! (I got a late start and wanted to get it wrapped up.) I knew that I was in a little trouble when I came in and announce that it was running. She said, “I know! And so does the rest of the neighborhood!” ZRT’s aren’t that loud, are they? LOL!

More garage time tonight. We’ll see what the final outcome will be. Thanks for the help.