I really need some help, I just dont know where to go with this. I apologise for the length in advance, I just want to try and list all that it is doing and what I have done so you have a better understanding of my issue.
2004 Sportsman 500 HO - about 2500 miles on it
Probably unrelated, but my issues started like this. I needed ball joints, front brakes and a starter. when I pulled it in the garage, it ran fine except the starter spun out after turning over a couple times.
After the repairs I went to back it out of the garage and notice right away it cuts out under load. (new starter spins out also)
If I give it gas to fast at any speed it will cut out, similar to when you are in reverse without pressing the yellow cut out switch.
I changed out the spark plug, inspected the wire and coil. nothing appears to be wrong there, checked it at night and cant see any arcing.
I pulled the carb off and cleaned it out, I did not see anything that would cause an issue here either.
If I pin the throttle going down the road it will maintain the speed, just wont accelorate. I tried choking it when doing this and it gets a little worse and would probably kill it is I didnt stop choking it. I also pulled the gas cap off and that didnt change anything either.
When I got it there was no gasket on the starter rope recoil cover (not sure what to call that) water was getting in there. I assume my starter issue is probably the bendix from getting wet though it appears to function properly when I pull it out.
Is there anything around the bendix that could causing the cutting out issue.
The air filter is a little dirty, but it does it with out the air cleaner on.
I also check fuel filter, I can blow through it fine, i put a T in fuel line a put a fuel pressure gauge on it and it shows zero, doesnt seem possible that it would run at all with zero pressure, gauge is a known working gauge. does this point to the fuel pump?
I am at a total loss here, I really dont want to just throw parts at it hoping i get the right one. if someone could point me in the right direction I would really appreciate it. I know a little about engines but am really a novice so if you could try to be clear about that would be great.
Thanks so much for your time and knowledge..

 

I have gone through a tank of gas, filled it and added sea foam since this started as well.

 

The ecm module can cause all sorts of problems on the 500.Even if it has been replaced under the recall. If it hasn't(You still have the BLACK finned Chinese ecm) then call an area dealer with your vin# for a replacement at no charge.Polaris Industries Expands Recall of ATVs Due to Fire Hazard | CPSC.gov If you have the silver Sure Power module even it can fail. Several on ebay. 2004 2006 Polaris Sportsman 450 500 Scrambler Surepower ECM PDM 2203348 | eBay Before you start throwing parts at it,best to have the manual and go through stator checks and the trouble shooting guide. Here's a cheap 5 buck service manual.2004 Polaris Sportsman 500 Service Manual PDF Download