My 2001 EdgeX 600 runs like poop. I haven't ridden It much in two years and when I did, it was to set it up for 660' drags. It seems to run out of juice when giving it more than 1/2 throttle. I thought it was some clutching glitch so I changed primary clutching to 62gram wieghts with almond/blue spring and secondary to R-12 helix with silver spring in #3 hole. Better but still bad. I removed VES and found one bellows with a rip in it. I have procured new orange bellows and will install them shortly. My thinking is that one torn bellows wouldn't affect performance this much. So while getting the bellows, I also got a new thermister, what most call a temp sensor. I've read that a faulty thermister will kill performance and the ones that came on this sled were notorious for malfunctions. I've also read about a yellow band on the replacement part. The part I have has no yellow band. It is Polaris part # 4010398. Problem is that I can't find this part number's application on the Polaris online parts search. http://parts.polarisind.com/Browse/Browse.asp The date on the bag that contains the thermister is 01/24/06.

I won't install this untill after I put my VES back together and test the sled to see how it does, but if the sled still runs poorly, I would like to know that I am installing the correct thermister.

Thanks in advance for any replies related to any part of this submission.

P.S. The carbs are clean and loaded with 410 mains which seem to have worked great in this sled in the past.

Yes, one blown bellow will cause performance issues. Sounds like you're set up pretty well otherwise. Not sure about the temp sensor...when I replaced mine on my 01, it had the yellow striped band on it. Maybe the newer ones don't have the band?

Regardless, I'd be the blown bellow was the culprit.

OK the bellows are in and performance is better. Still only goes well @ under 2/3 throttle. Time to put the new thermister in and see what happens.

Grrrrrr. New thermister in and still no-go. Back to the service manual.

I've now bled the system as per the serive manual procedure. Mabey a few bubbles were bled. Still sucks.

I can be going across the field behind the house @ 60 mph, 1/2 throttle and ~6800rpm, and when I hit the go lever the sled actually slows down with the rpm going with the speed.

Any else have a guess?

Sled sat for 2 years...bad gas...rats built a home in the airbox or muffler. Sacked out clutch springs. Hows it run on a stand?

im havin save problem. its ridiculous, dealer told me it might be my heat sensor? or somethin like that lol.

Is the VES cylinder hole plugged?

Carbs vented OK?

Nothing in Airbox?

Reed valves?

I'm just grasping at straws, here... somebody else with more knowledge than I, feel free to chime in!

Maybe your Brass gear for the crankshaft right in the middle is shot....That brass gear keeps the water pump pumping Antifreeze. Sounds like it's that.....take it apart right down to the crankshaft and find out....

Got great coolant flow. VES orfice into cyl is wide open. New gas. Clean air box. Clutches are clean, in good condition, and aren't malfunctioning.

I think that the actual slowing down from half throttle to WOT is the key. I've had sleds that wouldn't go faster or ran bad @ WOT but never had one slow down. This thing runs great from idle to 1/2-2/3 throttle.

What exactly does the TPS do?

Check your air hoses for the air box make sure they're connected to the air box properly too...if they ain't on properly then that's why your not getting max rpms

If by air hoses you mean the carb vent lines, they are on properly. One thing I haven't checked is the fuel supply to the carbs. Seems like the bowls would give me fuel flow for at least a while. The fuel line isn't in to great an area to remove and check. I should have checked it when I had the carbs off.

Maybe one of your pistons are no more good then....cause if you say you can't get max rpms, I'd check the pistons.....take it apart and take a look at the pistons...

What can happen from sitting in the garage too long like you say, is that a film of oil can build up on the top of your pistons and when you finally start it up that oil build up can break your rings, during the summer when parked, I start up my sled every week during the summer so oil don't build up on the top of the pistons, even when you're not using you still gotta fire it up once a week...

maybe your bellow ripped open due to piston ring debris.....check it out and keep me posted

Make sure the ignition key is in premium position. Check compression. Sometimes storage corrosion will seize the piston rings into the grooves and cause low compression, and poor cold starting.

Check reed valves also for broken/damaged petals.

Have you checked plugs? How dark are they? When you are having this problem at full throttle, hit the kill switch and hold throttle wide open till sled comes to a stop. Then, check plug color.

Engine sounds too rich. To confirm, hit choke briefly at wot and see if it gets worse or better.

I've seen a bad CDI do this also.

Good luck

What in the world are you talking about????
Where does an oil build up come from? Oil is injected into carbs to mix with fuel and then lubricates the crankcase and finally burns with combustion in the top end. This takes engine rotation and scavanging to move any oil into this area. How do you suggest it builds up on top of the pistons during storage??? You would have to fog the shit out of it (if even possible) to create the condition you are discribing?

Oil in the Engine from when it was last started. There will always be oil inside the engine no matter what....hello?

OMG do I feel stupid. After checking fuel delivery and deciding it was good, I removed the top of the airbox again and saw nothing. No grass, straw, hair, mouse tracks, whatever. I went ahead and pulled the shelf holding the diffuser tubes and discovered my hood filters sitting in the bottom of the box. The pieces of coarse foam that go into the holes @ the top of the hood. I wondered where they were cause I remember removing them when racing. Apparently me or my son put them in the bottom of the box for safe keeping. Runs like a scalded dog again, although I should back off the spring in the helix cause it's doing like 8200 rpm.

Check the small stuff first.

Dumb. Dumb Dumb!

Thanks again for all the replies gents.

There is no way piston..rings...bearing material or anything could get in the exhaust valve.
Check compression with a gauge...clean the carbs and check jetting...
How bout just going back to 10-60's or the stock 58's?

Glad you found the problem......good thing u didn't tear the engine apart like polaris800rules told u to do