main jet question?

[mean350]

i have a 350x and i want to jet it up. it has a supertrapp exaust and k n air filter.i think it has been jetted before but how do i tell. the main jet does not say anything on it. also do you guys think a 142 or 145 would work. i am running my supertrapp without the end cap or disks.

[TravEX]

Try a 140 first. That should be about right.

[mean350]

i think that is what is in it now because it ran good with the disks on and now i feels like it sputtering and stuff like that.

[TravEX]

Why are you running it without the end cap and discs? I would. The 140 should be right without motor mods. Make sure the air filter is clean, and do some plug chops.

[mean350]

it seems to have more top end and is alot louder. sounds awesome!!! i am going to buy a 142 and see what happens

[mean350]

i just cleaned the main jet off and there is a 145 in it now!!what should i do? every once and a while it will bog out from 1/4 to full throttle. should i go up or down?

[Wickedfinger]

You are making all noise, no power without ANY disks in there. That exhaust IS NOT designed to run as an open system. You need some back pressure to help extract the exhaust gases. Alot of guys will tell you that more disks = less power but also less noise, that is mostly true - but - you are also fine tuning your exhaust and general powerband characteristics with those disks. It sounds to me that your Jetting isn't your problem, its your exhaust. The megaphone part of the canister is the only thing in your exhaust thats working at all, and you are only seeing that gain at your extreme top end. You are missing out on all kinds of low end power without the disks. Try running it with 4 disks and your jetting woes might go away.

[mean350]

well i did not see any lack of low end power either. i can sit on my gas tank and ride a wheeleie. i think my main jet and needle jet was almost clogged shut too. i cleaned them but i cannot try it out because i have the motor out to paint the frame

[TimSr]

i am running my supertrapp without the end cap or disks.

Do you realize these two things do nothing but cancel each other out, and give you a bunch of obnoxious noise as a byproduct? If you are going to run it like that, it was a real waste of money to use a Supertrapp to begin with, since you are not using the features that make them a great exhaust.

Leave the end cap on, and add more disks for more top end. You take disks out to increase low end, but you dont take ALL of them out! Taking the encap off bypasses going through your disks, and if you are going to do that, your Supertrapp is a waste. Put your endcap on, and start with about 7 disks, and it will perform a lot better than it does now, and wont piss everybody off within 5 miles.

[TravEX]

^^^well said!

[mean350]

well my x came with the supertrapp on. the trike was only 250 bucks. my supertrapp is also broke so the bolts will not screw uinto the exaust. so i got no choice.