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Honda 400ex carb trouble

2162 Views 21 Replies 5 Participants Last post by  SlammedRanger
Hey guys I’m new on here ... I have a 2002 Honda 400ex I’m workin on for my buddy... it has k&n air filter and a excellerater exhaust by DG performance... it idled fine but as soon as you got into it it would cut out .. unless you turned the choke bout half on then it would run pretty good .. I need a starting point for the carb .. jet size and needle position?
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If anyone could help me I would highly appreciate it. I have a 2000 300ex and having similar issues. Starts right up fine, will idle, but the second I snap the throttle from idle to wot real fast it bogs out at first or will even die if I don't let off wot quickly. Seems like when I'm riding with a load on it, when I take off it's boggish unless I play with the throttle. I cleaned the carb. But noticed it has a 118 main jet. Could having a 118 jet and full fmf megamax exhaust be the culprit? Also has k&n with two 1.5 inch holes in lid.
Also forgot to mention it runs rich. Smokes slightly blueish oily smelling and plug was black crusty and dry. I'm assuming maybe new rings or valve seals? But could this also be an effect of my bike running like I previously explained?
Yes it gets worse with revving and riding although I haven't had a chance to rude it far enough or long enough to determine whether the smoke goes away or not but I've let it idle till warm and red it and still smokes. Not sure on how to tell if the jets are dyna or oem. Just says 118. I ordered an fmf power up jet kit, will hopefully be here tomorrow. I will switch the jets and reclean and see what happens. Do you think rings should be added to my shopping list as well?
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