Polaris Scrambler - Backfiring issue's

[HondaToy]

Picked up a 98 Scrambler 400 2 stroke, and am trying to work some bugs out, the quad runs great in 2wd but starts sputtering and backfiring when I engage the AWD. The battery had been removed, and I have since learned that this shouldn't be done on a Polaris, I installed a battery and it now backfires in 2wd. Obviously dealing with some electrical issues, just wondering if anyone has any advise,
Thanks!

 

[rknight111]

Garryese is very knoledgeable on these, I PM'd him to take a look at your question.

 

[BIGFOOT]

Picked up a 98 Scrambler 400 2 stroke, and am trying to work some bugs out, the quad runs great in 2wd but starts sputtering and backfiring when I engage the AWD. The battery had been removed, and I have since learned that this shouldn't be done on a Polaris, I installed a battery and it now backfires in 2wd. Obviously dealing with some electrical issues, just wondering if anyone has any advise,
Thanks!

U maynot have any working bulbs since the machine was run with out the battery... Not sure what is going on with the back fire, But I would check the carb out ( Ensure U not overfueling) or maybe U got a bad plug !

 

[Garryese]

First off... don't run anything with a charging system without the battery connected.

Do yourself a favor and start the troubleshooting with a new spark plug. Can you post a pic of the existing spark plug? A bad plug can cause a backfire and the rev limiter is at fault, it will foul a new plug quite quickly.

Is the battery you installed a good battery? If so, make sure all the lights are working as Bigfoot suggested. Do you know of any other electrical or fuel related problems?

Is it actually back firing or is more like it is running a rev limiter (studdering)? AWD circuit has a rev limiter tied in under certain conditions (prevents engaging AWD above a certain RPM). Is the AWD light on? Are the front wheels engaging when in AWD?

If it is an actual backfire: Is it worst cold or warm? Does it backfire on acceration or deceleration? Check the intake boot between the carb and head for cracks or dry rot. Check the exhaust system for holes or loose connections.

 

[HondaToy]

Narrowed it down to the rev limiter, running without the battery must have fried it, I disconnected it and the quad runs great, just need to figure out how to bypass it to get the awd to kick in.

 

[Garryese]

The black wire on the rev limiter goes to ground; cut it and no more rev limiting from the rev limiter.

 

[powderpusher]

where is the rev limiter located on these polarisis,s as i am having simular problems with my explorer it back fires on excelleration and has no power but will idle all day also my awd does not seem to be engaging now would like to locate the rev limiter and disconect it to see if it is my problem

 

[Garryese]

where is the rev limiter located on these polarisis,s as i am having simular problems with my explorer it back fires on excelleration and has no power but will idle all day also my awd does not seem to be engaging now would like to locate the rev limiter and disconect it to see if it is my problem

What year and engine size. Most rev limiters on Polaris' are located under the front pod. The are two smaller black boxes; The one with yellow wires going to it is the volatage regulator; The other one is the rev limiter.

 

[powderpusher]

it is a 98 sportsman 500 4 stroke it will idle fine and drive as long as i dont try going any more than half throttle as soon as i go over half throttle it bogs out and back fires and the awd quit working the front pod you mentioned is it located below the headlamp and contain all the wiring and circuit board thanks for all info dont work on quads much mostly old sleds also i was wondering if you would cause my starting problem changed out the solonoid cause the old one was pooched ,now it wont turn over with the ignition switch in the on position ,but will turn over with key in off position and have to turn it over that way then switch key to on position while turning it over to get it to start