So my girlfriend has a 2006 polaris sportsman 500 h.o fuel injected. It sat for 2 years wasnt stored properly with stabilizer. I cleaned the tank, fuel lines, throttle body. Electric clean spray in all the connectors. I have a motorcycle battery in it now for testing as the battery is toast. All new gas and some seafoam in it. The aircleaner is a little dirty and Im waiting on a new one but it is not too bad visually. Spark plug sparks and is a little carbon fouled but cleaned up and it seems to spark well. Fuel pump works well.

When I turn the key it turns over and gives one big rev and that is it. If I give it some throttle sometimes it will do a few revs. Seems to be a lag from hitting the throttle and engine response. Then it just dies or if it does a couple revs it will backfire before it dies. Makes the whole intake box jump.

I really want to get this fixed for her. She's gone with work for a few weeks so I have some time. Any thing is much appreciated !

Charles

 

Get the correct battery.Make sure you don't have too much slack at the throttle lever or the etc contacts can touch and kill the machine or cause back firing if the points bounce off each other. Maximum of 1/8" slack at the throttle lever. If it's too loose adjust the throttle cable. Another thing is the tbap wiring and connector having problems. This was a bad year on this happening. Sometimes you can wiggle the harness and notice an engine change. Codes may or may not be thrown on intermittent shorts if that's what's happening.Check the wiring leading from the sensors for any obvious bare wires or soft feeling wires that may have melted internally.Read the sticky post on 700/800 efi problems(includes all efi models) above the expert section.It goes in to the wiring and connector problems. Sensors were not normally a problem. Better tbap and tps harness kits than what Polaris supplied are available if needed from this site.https://otbpowersports.com/products/