Ok so my 400ex has not been running good first I took it to a guy to get the carb cleaned and he put a 120 main jet instead of putting back the 148 which was on the bike since I got it. So I felt the bike getting really hot an I decided to check the carb my self and I saw it had a 120. So I put it back how it was I put the 148 back and the bike wouldn't start unless I gave it a little throttle. It wouldn't idle at all. Wouldn't start unless given gas. If I hold it, it stays running but if I let it go it dies. My filter clean and I have no leaks. It also poped when I gave it to much gas. And I have two jet kits a dynojet one and another one which is a six sigma jet kit I don't know of you guys have heard of that one. So I did exactly what the dyno jet kit said I put a 165 and took the lid off (I was planning running no lid) and put the needle at the groove #3 and turned the mixture screw 3.5 turns and it did the same it wouldn't turn on unless given throttle and holding it. It would also sputter I can ride it only if I give it gas. What is wrong with my bike I tried both kits and it did the same I tried that six sigma jet kit, this kit has just that look just like keihn jets and came with a 42 pilot I tried all the jets did exactly what it said and the bike still did the same thing. What should I do ? I wanna jet the bike I have a pro circut pipe slip on and I wanna run the bike with no lid stock filter. What jets should I use ? My altitude is 3000 feet to 5000 feet above sea level. Thank for any help sorry for writing so much lol.
So I'm assuming you tried the new pilot jet that came with the kit? To me it sounds like a pilot jet problem. Also, I would run carb cleaner through all the little nooks and crannies in the carb again as sometimes when you "clean" it, dirt can actually move and get stuck somewhere else. Is it smoking at all or leaking oil at the head gasket?
It doesn't leak oil. It sometimes smokes white but it's not noticeable. It doesn't smoke black. The kit I have comes with a 168,162,158,152 and a 42 pilot. I took the lid of like the instructions said I put the 168 and 42 in there and it wouldn't turn on so I tried the 162 and it would pop when I gave it throttle not when I let go. Then it started doing that with all the jets I tried. What size jets would you recommend? Thanks for the help.
I believe Dyno Jet numbers to not match with keihin numbers, so if you are putting jets in that match keihins, try the 152 or 158 main jet and stick with the 42 pilot. 168 is very rich for just a pipe and no air box lid using keihin jets.
2002 400ex wont stay running.
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