Jetting help please

[Woodsrider]

I recently installed a new pipe on the 400, and had to rejet. I went to a 160 MJ and a 42 Pilot. backed the mixture screw out an additional half turn from stock and it still pops when I let off the throttle, and coast. Its a White Bros. pipe, running 9 discs. Under 2500 ft.

So what should I do next, up another jet size? Or raise the needle, or turn the mixture screw out some more?

[cals400ex]

is it a full system or slip on?

[hondarider2006]

put some high temp silicon where the header pipe and silencer connect. Tighten it up good so there isn't an exause leaks. Also I am running a 165 main jet right now. The temp is around 65-70, and it pops a little, not much though. The plug is near perfect tan though. This is with the air box lid on. Hope this helps some. -Nick-

[ewalker302]

I run a FMF megamaxII (discs) w/airbox lid on, & I am experiencing the same thing. I was getting bad backfires when I first got the bike. I rejetted & gained power, but still am experiencing an intermittent & softer backfire on decel. Im going to try dropping the needle 1 positon & turning out my air screw.


Let us know what helps, & I'll do the same.

[Woodsrider]

Thanks for the replies. I did some boning up on jetting and I think I'll have it dialed in the Sunday. I'll let ya know what I end up with.