Well lets see, If you don't think that it is the ETC control about the only thing left is to drain the carburetor. You may have some water in there. Water will effect the high end of the operating range first.

Also change the fuel filter.

You are at the mileage when strange things begin to happen to the carburetors on a Polaris 400 two stroke.

How is the choke circuit? If the engine is warmed up completely and you put the choke in the 1/2 position, does it change the idle or stall the engine? If it does this is good. If it does not change the idle characteristics it is pumping extra fuel into the engine.

The air screw on these machines is unique to each application but my machines ran the best when set to about 3/4. 1 in the winter. I tried 1 1/2 like the owners manual said but fouled out plugs on a regular basis

An air filter which has been soaked once has to be replaced. (Snow can also make a filter go bad)

You could have also picked up some foreign matter in your main jet. I know I had a plugged pilot jet once from purchasing gas too near the bottom of the storage tank. I got a double dose, water and a clogged jet.

Bad fuel can also cause corrosion of your needle jet. In addition to the fact that they also wear out.

Like I said, you are at that pivotal point in the ownership of a 400 two stroke. It might just be the best to completely rebuild your carburetor if the new air cleaner does not solve the problem. Good luck.

 

So Campy,

Did you get it fixed over the weekend? What was it?

 

Victory,

K&N filters for the Xplorer are backordered... they should be in by Friday...

More waiting...

 

Nothing like a hanging thread!

Campy

What did you find to be the problem? [img]i/expressions/face-icon-small-confused.gif[/img]

 

It was the air filter. I dropped in that K&N and it was like a whole new engine underneath that seat. That thing made a WORLD of difference.

 

TextWord of advice dont buy a POLARIS[img]i/expressions/face-icon-small-mad.gif[/img] Nothing but crap i had same problems

 

Changing the air filter is usually considered regular maintenance, you fool. If you had the same problems, apparently you never changed your air filter.

I hate to see what'll happen when the air filter on your EX gets bad. You'll be running around saying, "never buy a Honda! its all hype, they're really unreliable!"

Do us all a favor and get yourself out of the Polaris board, lest you have something HELPFUL to CONTRIBUTE.

 

Yel400exman,
Don't blame Polaris on this one! Their only fault was putting in a 2 cycle engine. Compared to a 4 cycle, they use twice as much air, and are far more sensitive to changes in vacuum as well as exhaust backpressure. Let's see, campy went 1400 miles before his air cleaner plugged enough to effect performance. It would be comparable with going 2800 miles on your ex. Sounds like a LONG time to not clean the air filter when put that way, doesn't it?

If anything Campy needs a whipping with a wet noodle for not checking the air cleaner every 500 miles like he ought to. SHAME SHAME [img]i/expressions/face-icon-small-blush.gif[/img]
Tip - for the stock filter, you can get an idea how dirty it is by holding it up to a light & seeing how hard it is to see through. Rotate it, and you will get an idea how much dirt is there.
Campy, glad you got it running. I have over 4500 miles on my Xplorer, and under $20 in parts so far (not counting oil, grease, and air filters). I wish every ATV we had on the farm would have done this well.