Help on jetting

[TRX250EXER]

okay, I have a 250ex and I just recently got the e-series slip on and the K&N jetkit and air filter. The thing is I tried jetting it to the stage 2 jetting that came with the dynokit. I followed all directions and it screwed everthing up. At first it wouldnt idle and we played with the idle screw and the air/feul mixture screw and couldnt get it right. Then I read that the e-series is designed for power gains without having to rejet. So i went back to stock jetting. Now it idles fine and runs better. BUT at the top of the gears it hesitates and shakes like it wants to stop right before it reaches the rev limiter. And sometimes backfires. Does this mean I'm still too rich?????? I think I have the air mixture screw all screwed up still from messing with it before. I dont think it cant be the main because full throttle worked fine before when I had a 106 in there. Now that Im back down to a 96 it does the opposite. So am I too lean or rich. What does the engine run like when its too lean?????? Any help on getting my engine to run smoothly will be appreciated.

[R-Crazy]

it sound like you running a wee bit too lean. try jsut moving the clip on you needle down 1-2 positions and then it should be okay. if is already down, go to a stage 1 jetkit and try. and read your plug everytime you make a change.

To Read: run it wherever you ride for about an half an hour. come back and take out your plug. the electrode should be gray and the rim around it should be black if your jetting is good.

hope this helps.

dave

My 250ex came from the dealer with the clip in the richest position (bottom). Do the Kits come with a different needle?

[TRX250EXER]

Yeah the dynojet kit comes with a new needle but I think that was the reason my was running poorly. it has 5 clips instead of 3 (thats better for more adjustments). But it tapers down to almost nothing. I think its TOO thin. I put my stock back in and I am running a lot better than with the dyno. Just cant get the hersitating to stop.

[Taco]

Originally posted by TRX250EXER
okay, I have a 250ex and I just recently got the e-series slip on and the K&N jetkit and air filter. The thing is I tried jetting it to the stage 2 jetting that came with the dynokit. I followed all directions and it screwed everthing up. At first it wouldnt idle and we played with the idle screw and the air/feul mixture screw and couldnt get it right. Then I read that the e-series is designed for power gains without having to rejet. So i went back to stock jetting. Now it idles fine and runs better. BUT at the top of the gears it hesitates and shakes like it wants to stop right before it reaches the rev limiter. And sometimes backfires. Does this mean I'm still too rich?????? I think I have the air mixture screw all screwed up still from messing with it before. I dont think it cant be the main because full throttle worked fine before when I had a 106 in there. Now that Im back down to a 96 it does the opposite. So am I too lean or rich. What does the engine run like when its too lean?????? Any help on getting my engine to run smoothly will be appreciated.

Installing the jet kit should have no effect on idle at all. The only jet that affects idle is the pilot jet and the K&N jet kit does not include this so i am confused. I would try it again. As for the air mixture screw just turn it while it is running and leave it where it idles the best.

The top is definitely the main jet. And from your description it sounds like you are running rich, but with the stock 95 jet in you cant be running rich either. Lean on the top end looses power, but no cutting out or backfiring. Are you sure you are not hitting the rev limiter? I was surprised at how quickly I can hit the rev limiter with just the slip on, 106 main and the air box lid off. If it does it in 2nd, 3rd, and 4rth, but not in 5th it might just be hitting the rev limiter.

if you take the air cleaner completely off and it runs better, it is rich, if you cover half the aircleaner with duct tape and it gets better you are lean....etc....good luck!

[9300EX]

the stock pilot setting for your bike is 1and7/8s out this means turn it all the way in go lightly don't turn it hard. then turn it back it out 1 and 7/8s of a turn good luck:D

[TRX250EXER]

Okay thanks, I'll try that, When I have the time i will take apart the carb AGAIN. I played with the air mixture a little and still cant get any good results. I do think that the needle is in the leanest postion because thats where we put it for some reason last time it was apart. But a high rpm's that wont make it backfire and sputter though will it? It does this in all gears and even neutral. just the high rpm's BEFORE the rev limiter. It idles fine now. But it acts like Im too rich and need to go down a main size but thats wierd since I put on a K&N and a pipe!! And if the pilot jet is in the wrong spot that shouldnt have any thing to do with High RPM's does it?? Anymore suggestions would be appreciated thanks.