350x running real bad (help!?)

[BIGCRIP28]

I took my 350x out today and it was running great. I just put a Krome power dg on and i also have a K&N filter. I put in a 145 main jet. I rode it around the yard it was doing good. Well anyway, i took it to my riding spot today and it ran good for about a hour. I pulled the plug and it looked alright (maybe a little rich). So i put in a new plug and i went haul arse down about a half mile straighaway and back. I stopped, killed it, burnt my hands all up gettin the plug out and it looked good. It still looked brand new. Then i decided to just go ride on the turnrows and fields. I was way back there and I decided to rip a wheely and I got it going then it fell and started crapping out. I then just kept the front wheel on the ground and tried a full throttle take off and when i get it revved up and past 1/2 and 3/4 throttle it just falls off. I rode all the way back to the truck (and tools) and it was still trippin. I burned my hands up again and pulled the plug and it was real dry black looking. I know this means it is running rich, but why. I mean it ran real good, and all a sudden it just starts running real rich. I tried the another plug and it aint that.

I got a 140 and 142 jet i think im gonna try. Any ideas why it did this?

[max]

Sounds Like You Might Be Lean. Like Your Float Bowl Is Draining Out To Quick. Id Check The Float. I Was Having The Same Problem With The Cutting Out And The Plugg Condition. I Ended Up Going Up One Jet Size, And Adjusting The Air/fuel Screw To Get More Air And It Cleared Rite Up.
Max

[cool_racer]

you need to look up the plug with a magnifiying glass. you just saw the end of it which isnt where you will get your reading from.

[BIGCRIP28]

the whole thing is covered in black crap

[hrc200x]

maybe somthing in the carb fell apart? Pull the bowl and take a look. What is the air screw set at? Does the spark still look good?

[MTS]

im thinking you didnt put the main jet in tight enough and it fell out and is rattlin around the bowl...iv had that befor lol

[BIGCRIP28]

i know you guys are gonna BS now. it was like i was hitting a rev limiter only not that high in RPMs then it would die off. well my dad was swearing up and down that it was electrical. so i took a coil off a big red and tried it and it did the same thing. at this point i was thinking it was way to rich jetted, but i couldnt figure out why it was running so good and all a sudden crap out. we were changing the main jet to the stock size (while my dad was like get that big red CDI and try it) i decided to peep in the airbox just to check. WELL!!, the dang air filter must have popped off in that rugged terrain and turned around and the solid plastic rear end (K&N guys know what im talking about) was against the intake tube and just about a 1/4 inch gap remained. it would run alright up to about 1/2 throttle and then die off. so, i put the 145 main back in and it runs like a top now. :D

[ATCnut]

Your 350X is not the first to try trikeacide by air cleaner. Last year at Oregon, my brothers 350X just quit going up a dune. There was a big group of people ..{going to the end of a long story}..... towed it back to camp ...{more story}...... five guys worked on the trike for an hour, and then someone finally looked in the airbox. The 25 year old stock airfilter had come apart. When the metal inner finally popped out, the foam sucked up into the carb. We stole a uni filter off of a trike that was sitting in camp and went back riding

[MTS]

least it was in one piece, my friend had his 200m backfire once after he squirted a bunch of ether in the carb he put the seat on fired it up-ran for a few secodsn then back fired....where like ok, try n start it again "hey whats that smell" see smoke from under the seat thinkin wtf?!? rip it off and the air cleaner was on fire LOL