hey yall, i have been reading these kawasaki forums for 1/2 year now so i feel like i know everyone of you. Well i finally figured out how to join. Anyways the reason i did is cuz i have a question. (problem) At higher speeds when i'm on the gas my prairie will sputter (surge) just for a second then it will get back up to power. ALso it backfires when i let off. It did all of this before my one performance mod. Please give me some ideas. Jetting?? Pinched hoses??? Dieseler

 

Sounds like you might have a rich mixture on the main. As for the backfiring on deceleration it is more than likely your air/fuel mixture screw. Try turning it out a half a turn at a time on both carbs until the problem is corrected.

 

If it's still under warranty, take it back to the dealer.

 

I like to work on my bike by myself. The dealer is aways from me and if it's something as simple as jetting of air/fuel screw than it wouldn't be worth the trip. Thanks for the advice i will mess with the screw. ALso, the main might be rich??? Please explain what and where the main is. I know deals with jetting. Which leads me to another question....... My spark plugs have a little bit of carbon build up, dark colored, not really built up too much, is this alright??? Diesel

 

If the porcelin tip of the plug is dark brown to a black color, it is jetted too rich. The main jets are inside the carberator on the bottom. You have to take the four screws out of each float bowl and pull the bowls off. The main jet is the one in the middle with the screwdriver slot in it. Take the jets out and see what number is stamped in them. The rear carb should have a higher number than the front one. If your plugs are black, i would start with five numbers higher, and jet accordingly from there. When you are testing your jetting, use the the "plug chop" method. This simply means run it wide open and turn the key off. Take it out where you have got some room to run. Go "WOT" which means wide open throttle, for about 200 yards, turn the key off and coast to a stop. Now take the plugs out and check the color. I hope you understand all this and it helps you.

 

Thanks for the info venforcer. I just gained a lot of knowledge about carbs. The carbs are probably the one thing i know very little about. There is a lot to understand about them. Anyways, could the jetting be the reason for the backfiring??? Also where is the fuel/air mixture screw?? Outside of carb, or inside? Also are the pilot jets right by the main jets?? One pilot jet per carb??? I just want to know as much as i can before i take everything apart. I really apreciate you guys for helping me out. I with i could be of help on these forums. But my knowledge is limited compared to these people who have taken many machines apart and put back together. Also maybe you older guys have many years on me as i'm only 21. THanks again
Diesel

 

Its kind of hard to believe you now have a rich condition after adding a napa hase (more air).
When you read the plugs, I beleive you read the base ring on the plug not the porcelain for air/fuel mixture.