Hopefully someone can steer me in the right direction. I have a 98' 500 Sportsman that is giving me fits. The motor will spin, but not crank. I had
a friend (mechanic) look at it and he said it didn't seem to be getting a consistant spark. I'm not a mechanical genius, but if it backfires after trying to crank it has to be getting a spark doesn't it? Could this be the CDI box? Any input would be greatly appreciated.

 

spray a little of starting fluid at the air filter while starting it. that'll tell you its a fuel delivery problem if it starts for a few seconds.

 

or spray gasoline to it with a spray bottle.

 

it might still have limited spark which is igniting the gas causind it to back fire. you should be able to pull the spark plug and see if it's firng all the time. if it was running and was acting like this i would almost say the cam lobes were worn and not letting the valves work right like some of the earlier 500's did. imo

 

I appreciate the responses, I've got a few things to check this weekend. It's been dead for a few weeks now. Now that deer season is over I seem to have a little more time on the weekends.

It was running strong, came back to the camp and turned it off and then after sitting for a couple hours it wouldn't start. It's almost like this thing has a ghost. Bought it from a person I know that had the atv in his shop for the past 5 years without it being run. It's a '98 model with only 460 miles and 60+ of those are mine.

 

did you do a service on it from setting that long w/ out running it? if the bike has a dirtly carb where the jets can be partly plugged it would be staring it for gas. just a thought.

 

Check the engine oil and make sure its not full of gas, the needle and seat in the carb can go bad and if the gas isnt shut off while sittin, it will fill the engine and air box with gas.

 

you know if its been sitting stored for 5 years save yourself fustration and time. take out the carburetor and disassemble it and soak it in carb cleaner over night. then clean out all passages with carb spray cleaner and then blow it out with compressed air. thats a must do on any machine after even sitting for a couple years or even less.

 

Allright, I'm still having issues with the Sportsman not starting.
It will spin the engine over all day and not fire up.

When turning the engine over with the plug out I get a little spark, doesn't seem to be very strong though. It actually seems to get a little stronger right as you let off the start button, if that makes any sense.

1)Have a friend with a spare cdi box, we tried it and same problem. Assume his was good.
2)Pulled the coil off and found that the wire going to the spark plug was loose, couldn't make it get good and snug so bought a new wire/sparkplug boot. (Should have taken some lube with me to the dealer for that one.)
3)Have checked the etc and the on/off switch and both seem to be working properly.
4)Do not think it's a fuel issue, but just to eliminate the problem tried
starting fluid at the intake.

Any suggestions on what to try next, even if it's just items that I should try and eliminate before I end up having to take it to a dealer?

Any help would be greatly appreciated. Thanks guys!!!

 

In addition to the above I'm in the middle of tracing wires and making
sure they all have good connections. Cleaning the terminals and using dielectric grease on them.