Supertrapp jetting

[250sx]

I just installed a Supertrapp on my newest (to me) 350x. It runs great, but pops when decelerating. That means I need a bigger main jet right? Just checking before I start fooling with it. :thumbsup:

[Dammit!]

I'd richen the entire thing a little. Lower the needle clip one spot, tighten the air screw 1/2 to one full turn and go up one size on the main.

[chrisr200x]

My cobra is the same way on my 350x. pops and backfires a bit when I let off the gas. I thought that was normal.

Its when it bogs when you hit the gas... its time to rejet.

You can hear what I mean on this vid. you can hear that loud ass pipe over the rest of the bikes. lol

http://www.youtube.com/watch?v=Y7iM--zPnGM

[NOS_350X]

The poping when decelarating is normaly more the pilot than the main.

[250sx]

It's an '85 motor with a stock '86 carb. Care to guess what I should get? :shrug: What's stock? I hate jetting. :cry:

[chrisr200x]

Your using an open airbox or aftermarket filter? sometimes you can just get away with adjusting the clip on the needle. can't remeber which way it goes though. up or down. and messing with the air screw. I hate messin with carbs too. Oh, and my plug is fine. :thumbsup:

I'd start there before you went and bought jets..

[200x_Basket]

try a couple plug chops 1st. it seemed to be running great.

[250sx]

It runs great. Just want to get rid of the popping when decelerating

[chrisr200x]

LOL.. I think that popping is kinda cool. It dont hurt performance at all.. (and my old supertrapp on my sx did the same thing) so I thought it was normal.

I put the stocker back on the X now anyways. that pipe is way to loud for my liking.

So that can be remedied by changing out the slow jet? I never knoew that! When I added the ST and the K&n to my 250sx I had to go up one size on both the main and the pilot. I also had to move the clip one notch. it still made that popping sound tho.. but ran alot stronger. Just keep an eye on your plug so It aint running white and lean.

[NOS_350X]

Most people dont realize how much power your missing out on when you dont change your pilot. The poping is a bad sign of a lean mixture and it will drasticaly shorten the life of the enigne. If its poping your loosing power, and your risking the engine.

[chrisr200x]

Most people dont realize how much power your missing out on when you dont change your pilot. The poping is a bad sign of a lean mixture and it will drasticaly shorten the life of the enigne. If its poping your loosing power, and your risking the engine.

That's odd as I was keeping a close eye on the plug. it's dry and brown just like its supposed to be. Of coarse not all bikes are the same and I'm sure location has alot to do with it.. along with numerous other factors I'm sure. I'm sure 4 strokes ain't as finicky as the 2 smokes too.

Good info tho... :thumbsup:

[NOS_350X]

Looking at an old plug dosent do a thing. Gota get a new one in there and see what its looking like.

[Rex Karz]

A Supertrapp flows a lot more than a stocker. By all means go up 2 sizes on your main and 1 or 2 on the pilot. More power, no pops and runs COOLER!