it will idol like a champ but backfires as soon as the throttle is pushed.

already replaced:
spark plug
air filter
Carburetor Intake Manifold Joint Boot

 

First thing is do you have the Kokusan ignition system or the Ducati? Change over to the updated Kokuan started on 2004 models built after 2/3/2003.You might have one of the early troublesome Ducati ignitions. Easy to tell. Kokusan has a separate cdi and coil,Ducati has combo cdi/coil pack. Both are under the front panel.

 

will check in the morning
Thanks

 

would that cause the backfiring through the carb.?

 

Yes backfiring among other problems such as hard starting,erratic idle,excessive fuel use,and some would dies and never crank back up. If you happen to have the updated Kokusan,the problem maybe carb related. Cleaning doesn't always help as carbs have constant wear on the float and needle and seat,slide needle,etc and the ethanol fuel doesn't help either. Good kits are out there that can at least eliminate the carb as the problem.New Carburetor Rebuild Kit Polaris Sportsman 600 4x4 600cc 2003 2004 | eBay

 

it has the Kokusan,

Question, is there a way the safety throttle to keep it limited in reverse can be hung up and keep it from running right?

 

Haven't had one happen as the limiter is in the speedo now and not a separate module,but anythings possible. You can try pulling the speedo connector and see if there is any change. Here's a cheap 5 buck manual that has the speedo section trouble shooting guide along with wiring diagrams that can help.2004 Polaris Sportsman 600 Service Manual PDF Download You also might try some electrical contact spray in the cracks of left control switch and push the over ride button several times.May be as simple as a little dirt or corrosion buildup causing problems.

 

Ok. I bought an 04 sportsman 600. Ran amazing when I test drove it. Got it home and it's doing the same thing as described above. Idles fine, as soon as I begin to push the throttle, won't rev. Starts to bog out. When I pull the choke out, it will run better (not great). Pulled the carb apart and cleaned it. Changed the cracked intake boot. Put it back together and it ran amazing for about 5 minutes then goes back to the same thing. WTF? It only has 453 miles on it! Tried disconnecting the speedo

 

If built after 2/23/03 should have the Kokusan stator kit. I'd still pull the front panel and check.If it runs better with the choke out that's telling something also. Could still be needling a carb kit as cleaning doesn't always help or possible the fuel pump is weak. You can pull the line from the carb and crank the engine over. Should be a steady stream of fuel from the pump. If not replace it.If needed you can get the manual too that can help.Has a good fuel section along with electrical tests and check outs.2004 Polaris Sportsman 600 Service Manual PDF Download Both you and jananderson63 can use some electrical contact spray between the crack and crevices in the left control switch and work the over ride button several times. Not unusual for these to cause problems also. There are people that have bypassed the over ride button.http://www.idofishing.com/forum/show...everse-overide

 

ok. I put a new fuel pump on it. Started it up and it still ran terribly. I put a rag and compressed air in the fuel tank and put it all back together and it seems to be running fine now. Maybe I had something in the tank blocking the fuel? Maybe it was the fuel pump? Dunno. Just glad it's running