I see you have given a lot of polaris help.. I have a 2000 polaris sportsman 335. just did top end( bored .10 over and valve job), new fuel pump, new cdi, new after market carb and air cleaner. engine starts, idles perfectly but when I even attempt to throttle up I get a bogging. Its in the throttle low range. when it gets hot it still bogs but its less and at times i can get it to throttle up into secondary. I checked for air leaks and used carb cleaner and got no change in engine speed when spraying carb area , vacuum pulse line to fuel pump, and air box connections. Only when I put my hand partially over airbox intake it will throttle right up. When I did top end it went out to a guy named ANDY in texas who machined the cylinder and redid the valves. I get no blow bye. He did see slight wear on exhaust cam lobe but told me that after cleaning up it was satisfactory.I am disabled and purchased this for hunting and way overpaid and now have spent a lot already trying to solve this problem. my buddy thinks this is a vacuum problem. I think since we changed the size of piston and cylinder maybe a jetting problem with not enough fuel...any thoughts?

 

Check that the jets are the same in the knock off carb as in the oem. Should have a 150 main jet,40 pilot. Plus pull the BLACK wire from the reverse limiter module and see if it helps. They can cause limiting in forward range also if faulty. Item #37.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse You can always check if vacuum is ok along with the fuel pump by pulling the fuel line from the carb and cranking the engine over. Should have a steady or pulsing stream of fuel if everything is working right.

 

will do that. Im leaving on a road trip for 6 weeks and will address it when i get back . thanks for the reply...mike

 

I do have a pulsing flow of fuel when cranking with spark plug disconnected

 

Then you can eliminate the fuel pump or a vacuum problem.Try pulling the limiter black wire next,then check out the carb jetting. Plus we didn't have cam problems on the 335 like we had with the 425 and 500 engines.

 

Hello again old polaris tech. We spoke awhile back. just got back from cross country. I backed out pilot jet adjustment on bottom front of carb . real hard to get too. I have it out a lot more than the 2.5 turns it says to set it at in manual. I unhooked and taped up the black wire on limiter and bypassed the reverse override button. still getting a bogging but gets better when hot. I had this thing bored .25MM with new polaris piston. I noticed when its bogging its from the time I push the throttle lever which means its the primary but when i put my hand over breather box it races up and much better

 

If air box and filter is installed and it runs better by choking down air,then it's usually running lean on the main jet. 2.5 turns out is pretty good for the pilot(idle jet) which this screw controls.Shouldn't be out more than 3 turns max. Plus did you ever check the jets against the old carb? Could be where the problem is.

 

From what I learned the primary jet control the beginning of throttle travel and then the main gives fuel about a quarter to half throttle....is this right?the bog begins as soon as you hit the throttle ...even a little bit

 

also I have to remove carb and check the jets

 

Yes primary(pilot jet) controls idle to about 1/4 throttle,then secondary(main jet and jet needle) take over from there.