just took a ride with my new pro curcuit slip on and a 152 main jet........stock is 148


i was disapointed with the performance............

on the way to the trail it was spuddering at full throttle, but then it cleared up....

it feels like it got a little more bottom end,
but it feels like it lost alot of top end power..........
which was where all the power was when it was stock

so i pulled the air lid off and it seemed a little better

it had way better top end when it was stock........

did i go to big or small on the jet???????????
what gives

 

It sounds like it is running rich so I would try the stock jet and see if that helps. Check the plug before you do anything though. It will tell you if it is running lean or rich.

 

what color am i looking for on the plug???????/

 

well,
i did the plug check and it looked kind of whiteish gray, on the tip

took it up the road to my buddy at the honda dealer.........

thay all said it looked a little lean and recomended a 155 main jet

he even knew it was sputtering.....
and i didnt tell him.......

 

i called pro curcuit and they said to go 1 size from stock like a 150....

i told him it was running a little lean with a 152 so he said try anything up to a 158......
what the he!! kind of tech support is that.........[img]i/expressions/face-icon-small-mad.gif[/img]

im getting tired of this jetting crap....

 

Actually, tech support gave you good advice. Rejetting is dependant on a lot of things, so if they were to give you an absolute value that wouldn't necessarily be right.

Try the 155. As much of a pain it is to do it, it's better than having to replace a cylinder head.

Did you adjust your needle too?

 

Corpsie,

i guess your right about the tech support.....

im going to get the 155 tomarow

and no i havent adjusted the needle.
do i need to???????????

how do i do it??????????


thanks

 

I am no pro, and no slam intended, but you should probably take the time to re-check everything as far as the carburetor bowl, etc, to make sure all is well. If anything, you should be running lean and that should result in a "flat" top-end, not a gurgling top end. I have a 250ex with the same pipe and K&N filter and drilled airbox lid. I went from a stock 95 main to a 120 now. Just my $.02.

 

unfortunately, I can't help you with the needle. I imagine you can find it using a forum search.

 

You may or may not need to adjust your needle. If it seems extremely cold blooded or if it "coughs" then you may need to move the needle. If you have never been in the carb, the needle is accessed through the top - you will probably need to remove plastic/tank cover to make your life easier (I don't have a 400). The needle has grooves in it and your adjustment will allow more or less fuel in at 1/4 to 1/2 throttle approximately. I moved mine because of the pipe and K&N. Moving the clip DOWN a notch makes the needle ride higher and therefore allow more fuel in this throttle position. As far as mains go, I think its FMF that has a website with suggested jetting for their pipes - should be similar.