440 ex trouble

[grizzlykev]

can any body give me some info on a 400 ex it has 440 kit in it with the piston shaved to give it 10 ?1 comp its running lean i bought the bike used and dont now what jetting should be.it wont run without the air box off the main jet is 54 dont no what the pilot is it starts hard as they have the choke out of it and has an awful flutter at low rpms the bike runs fine other than that .thanks for any help

[ReconRider25]

i dont know but you could try putting this in the powertrain forum or the open forum where theres more people. you might get an answer faster.

[mikeboone]

Originally posted by grizzlykev
can any body give me some info on a 400 ex it has 440 kit in it with the piston shaved to give it 10 ?1 comp its running lean i bought the bike used and dont now what jetting should be.it wont run without the air box off the main jet is 54 dont no what the pilot is it starts hard as they have the choke out of it and has an awful flutter at low rpms the bike runs fine other than that .thanks for any help

Is that one big sentence? :confused: Anyway, #1. the main jet CANNOT be a #54. That is the pilot jet (maybe little too big). The main jet is right beside the pilot and will be a #140-180 or so. Try a #175 main and #50 pilot and see how it does. You want to start rich and work down. You can access the main jet w/o taking the carb apart--take the small cover from bottom of carb and it's in the hole. DO NOT over tighten the jet as it strips easily. **Good luck and have a experienced friend help if you arent familiar with the carb and related parts.

[jb500ex]

your going to have to keep the air box lid off too. get an outerware cover

[markk]

Talk to PATTY440 he had that problem but now he has it fixed and he also had a problem with blowing head gaskets but he shaved the dow pins and that works Id ask him i could probley help you

[PATTE440]

mikeboone pretty much hit it on the nose and it still all depends on a few other things. Full system or slip on, port and polish job(if one) and where you live. ALTITUDE AND HUMIDITTY I live in southern Illinois and the settings I have in my bike is a #48 pilot and a #180 main with the air box lid off and choke out. I did have a bit of trouble sucking water even with an outerwear so I got some thick foam and put around the air box on the SIDES most of the water that gets into your air box is splashed in by your tires I haven’t had trouble with water since I did that and I have hit some holes to try and get water in it. if you take the lid off pull the plug on the bottom of the box that way if you do get water in it will drain.
Another thing pay close attention to is when you go about changing the MAIN jet every now and then instead of just taking out the main jet the needle jet holder will come out to and the needle jet will fall out so be careful

[ILGNCC400EX]

i bet u a dolla u used zip ties 2 put that foam around that airbox

[PATTE440]

Yep in my life I would rather wear a necklace made out of zip ties then GOLD