2001 scrambler 500 2x4 won't rev up
 

I am currently having a problem with my Scrambler 500 2001 model it idles fine but does not rev up. if I put my hand over the intake area on the air box it will let me rev It Up. it was running fine and just started doing this. The contacts are not touching in the throttle and it idles fine. I sprayed carb cleaner on the intake boot to see if it has a vacuum leak and it did not change the idle. Diaphragm looks fine on the top of the carburetor. Can help would be appreciated. Thank you in advance.

Air box sealed good,air filter clean? Sounds like a lean condition if blocking the air intakes helps.Pull the fuel line from the carb and see if you have good fuel flow in the on position and reserve. Problem could be as simple as a stopped up filter or valve. If fuel flow is good then possible some dirt or bits of deteriorated fuse hose can get trapped under the needle and seat blocking off flow to the carb.If you have to remove the carb I'd go ahead and install a kit if its never been rebuilt.Polaris Scrambler 500 4x4 1998 1999 2000 2001 2002 Shindy Carb Rebuild Kit | eBay Float level has to be set correctly or you can have problems also. Look over this thread on the BST40 carb. On a Ktm but float etc are the same. Shows how to set it correctly.The BST-40 Bible | Adventure Rider

OK I will give that a try sorry for the double post. I am just getting back to the Atv thing, the older kid stopped riding so I got rid of everything and now the little one wants to ride. I used to go to gen3usa but that place looks almost dead.

we are still alive at gen3, granted u may not get a response as quikly as here a lot of ppl pop in at least once a day

Well I got it fixed. I got the carb rebuild kit in the mail. I went out to rebuild the carburetor. I found a piece of debris or seed in the main jet. I cleaned it out and put it back together. It is running great. I did buy a rebuild kit so I guess I will have that to use in the future. I also bought some feeler gauges and a caliper to check the camshaft. I am glad it was that easy. I will just put it back together on my next day off. Thank you for all the help I am sure I will be back to ask more questions. Plus I like to read all the other threads as well to learn things.

The valves seem tight .006 on the exhaust and about .003_.004 on the intake if I remember right. I thought about loosening it up but decided against it. Any thoughts?

.006 on both intake and exhaust...OPT gave me a good tip when doing it "Best to have two feeler gauges so you can accurately set the exhaust clearance.Slip one under one side and temporarily adjust to where it has a little drag,adjust the other side to specs,then go back to the other side and adjust it. All you're doing is keeping equal pressure on the forked rocker arm. Intakes are no problem,just adjust at .006."

Probably small piece of deteriorated fuel line blocking the jet. You can thank good old ethanol fuel for this. I've found plenty of black specs from fuel lines floating around in fuel bowls from this crap. Keep the fuel filter change regularly and use a good stabilizer like Marine Stabil or Star tron to help cut down on ethanol damage.