Ok,what all have you done?

 

Well we bought it a couple months ago not running, just been sitting up for years and tried cranking it well it fired right up but it was like it was halfway running, just piping and choking and completely unresponsive to throttle we replaced the spark plug and ordered a new carb offline. We put it on and it's still doing the same thing. Not sure what to do next. We replaced the carb, spark plug, fuel pump, fuel filter, and fuel lines. Still doing the same. It will also backfire through the carb sometimes

 

Have to ask this.. Do you have the air box and filter back on? If not they will run crappy. Have had a lot of people not mention this when posting.Not really crazy about these knock off Chinese carbs in place of the oem Mikuni. If the carb was at least salvageable a good rebuild kit could have been better. Shindy Carb Repair Kit For Polaris Sportsman 335 99-00 03-424 | eBay Plus the carb may not even be jetted the same as the oem.. Either way since it's doing the same thing with a different carb, a couple things like have you adjusted the valves? They set at .006 intake and exhaust.If too tight it can cause one to run crappy.Plus I'd have a good look at the cam lobes to make sure that the exhaust lobe(like the 425/500 engines) hasn't been ground down.Popping and back firing,but a good idle is what these machines did with flattened cam lobes. Another thing you can try is to pull the black wire from the reverse limiter module and see if that helps.They are bad about shorting out and can cause limiting in forward range also. Limiter module is item #36 on the parts break down.1999 Polaris SPORTSMAN 335 (A99CH33AA) Electrical/Taillight A99ch33ia | Cycle Parts Warehouse If that doesn't help,pull the black kill wire from the cdi to isolate it from the ignition and left control switch.

 

Yes I'm not a big fan of the carb either it was just a quick fix, I still have to old one to rebuild and keep as backup. Also we tried my carb off my 325 (oem carb) and still was doing the same thing. Have not checked the timing, not sure where or how also not sure where or how to check the cam. Are the 335 bad about grounding the cam off too? I will try the reverse limiter thing and also the cdi box. It will idle but it idles crappie, not a smooth idle at all and does nothing at all when you touch the throttle. Also if you move the throttle linkage on the carb itself it won't do anything either. It basically is running like it's on choke the whole time.

 

Yes pull the limiter wire first. You can leave it unplugged as all the limiters would fail. Once you get it running right you don't have to push the over ride button in reverse to have full power. Checking valves and cam isn't that tough. Pull the valve cover and spark plug. Pull the recoil over slowly and watch the INTAKE rocker arm go down and start to come back up. When the cam sprocket alignment pin is dead center of the head you're at tdc. The two valves can be checked/adjusted then. You can tell for sure if the cam lobe is ground down,but not many reports on this happening. Different cam than used in the others obviously with only the 2 valve system but no harm in checking. Compression test on these are similar to the 500 since it has a compression device on the cam end. Around 45-50 psi on average. Plus here's the pics on how the cam sprocket alignment pin looks at tdc.The 335 uses the same sprocket part number as the 425 and 500 engines. Also you may want to check the compression release spring. If it's broken they'll run like crap also.

 

Ok I will try that after work and let you know what I find out. I know the compression was good we checked it.

 

Pulled the black wire off of the cdi box ad it ran fine just idled a little high what does that mean?

 

Make sure you only have 1/8" slack ONLY at the thumb lever(can't be tight or too loose and the cable adjuster is down from the throttle housing.) Then see if you can idle the carb down with the idle adjuster underneath the carb. If it runs ok,no bogging(you can't kill without using the choke to choke it down or hooking the wire back up) the main problem can be in the ignition switch or the left control switch. Spray some electrical cleaner in the left control switch and work all the switches back and forth. Plus check the connectors at this switch and its wiring where it terminates under the front panel. Same for the ignition switch check for any bare wires. Then plug the cdi black wire back up. If it still limits the problem could be that you need a new left control switch,ignition switch or in rare cases the cdi kill circuit itself can be faulty and causing it to limit.PS are you sure it's the black wire from the cdi or reverse limiter you pulled?? If it's the limiter then most of the problem is solved except the idle adjustment..

 

I'm sure it's from the cdi because you can't kill it without choking it

 

Ok then go through the tests that I mentioned on the switches.Plus make sure on the 1/8" slack on the thumb lever and idle adjustment.