Here is my dilemma, the quad was becomeing harder to start and just not running very well. So I took and started by checking and cleaning the air filter also replaced spark plug. Not much improvement.

I then took the air box off to see the carb better, it looked dirty and a little build up on the needle. Order a carb rebuild kit and rebuild it, well put it back on starts a little easier but it bogs down real bad when you give it more throttle and the overflow on the bowl starts to run out pretty good. Can also see fuel just squirting out the hole were the needle goes in.

I am stumped

Is it possible that the fuel pump is over powering the needle and seat that is attached to the float?

Thanks,
James

 

The BST40 carb has a bad rep on leaking! Part of it is the way the needle valve is held in place by the float assembly alone only by pressure when the bowl is screwed on! I've tried adjusting them to no ends,replacing needle valves,changing to different size o-rings on the valve,etc and on troublesome carbs have still had em dribble out the overflow! I'd recheck that you have the float needle still attached to the float tab,could be part of your problem? Also check that the air jet at the back of the carb is open. Wouldn't think the fuel pump is the problem,usually pretty reliable. Just mainly the design of the carb! Check posts on problems with this carb and you will see several posts on leaking problems people have! If you can't completely stop if from dripping I would make sure you have a long enough drain hose that goes down under the frame! Some only leak at idle,some a little while running! Also on a different note the 2004 had the ecm recall if you haven't done so and also a bulletin on pinched plug wires(had a few of those I had to replace) OPT

 

The blue one I have had some wiring issues when I first bought it, pinched wires, dealer fixed.

This is on my green one, it has always been really good machine.

What is the ECM recall?

I will pull the carb back out and check what you suggested.

Thanks,
James

 

2004-2006 Sportsman CARB model 500s had the ECM recall along with other carb models during this period!. Just look up under the front panel under the headlight pod and if you have a BLACK finned module (Chinese), it needs to be changed out to a silver Sure Power module.They can cause varied problems from engine overheating,no charging situations,to wiring damage and possible fire hazard! No time limit under this recall and is under warranty!. OPT

 

Looking up the recall, my 500's do not fall under the range of vin #'s I found.

But looking at both machines they do have the black finned box you described.

4XACH50A74B406953 built 7/13/2004

4XACH50A74A308687 built 2/09/2004

Is this something the dealers will fix with out a hassle? or do I have to have a paper trail to get them to do it? Unfortunately the dealer I bought these from went out of business a few years back, but do have a couple dealers that are still close to me.

Thanks,
James

 

On the Atv Quad News website under atv recalls, the Polaris expanded recall lists 2004 model Sportsman 500s along with the original 2005 and 2006 models that were affected. Print this list and show it to your dealer. OPT