I just changed my jetting and filters on my raptor and now it is sputtering when i give it any gas and it backfires. There is no airbox, dual filters, 160/165 jetting and 2 3/4, 3 on the mixture screw. Does the sputtering mean it is rich or lean? what causes that backfire? how long do you need to run your engine before you can tell if the color on the plug?

 

any ideas?

 

One idea is to check your float level, it will cause problems when too high, also make sure you choke is working properly. Do you have a pipe? Does it backfire when you give it gas or when you let off the throttle?

 

i checked the float just a little while ago. do i need to do it again? I have full pipe and no airbox with dual k&n filters. i have a dynojet kit. running 160/165 mains. pilots are stock. clips are 3rd slot from the top. it backfired when i lot the throttle off. it had been running for about 20 seconds before it backfired

 

I'm not entirely sure, but I think when backfire occurs after you let off the throttle it means that it's running lean. I'm not too sure about the dynojets, but I think you might need to go up on the mains and the pilots....anyone correct me please...

 

what would be the next pilot up? 25?

 

Yuup, I would go with 25 pilots and 2 1/4 and 2 1/2 turns.

 

mmmmm....I can't quite remember, but with my GYT-R kit, I think it was 27.5...

 

You might try the 155/160 setup....The best way to check your plug is to run a few miles on it first to get some color.Run the bike under a load for about a minute or so at 3/4 to full throttle then pull in the clutch, hit the kill switch but leave your throttle wide open all at the same time....coast to a stop and then check your plug.Try that if ya can and that should tell you if you are to rich or not.hope this helped a little.But hold on and keep reading cause there are a bunch of guys out here that know way more stuff then I do about jetting and I'm sure you'll get some better advice.[img]i/expressions/face-icon-small-wink.gif[/img]

 

that sucks. that means i have to order one now. where is a good place to order a pilot from? if i went up to a 165/170 would it maybe help? also with the mixture screw. change to 2 1/4 / 2 1/2