Here's my mods.
Bored to 416
11.1 JE piston
k&n air filter
port and polish
lectron 38mm carb
WB rev limiter
XR400 cam

What i need help is that this thing will not idle. My engine builder which is pro at this stuff said that it's a race bike and wasn't going to idle. When i start it, it will idle for a while, but once you get going it will not idle. Can anyone tell me why? Is it maybe the carb or something? He jetted and everything. I think maybe the jetting might be off b/c i'm running through plugs left and right, but i know it's a built machine and i have been puttin it around a little riding with my girlfriend. So i think thats why i was foulin' the plugs.

 

Sorry Aaron10. I can't help you with you problem. I'd like to ask you a few questions if you wouldn't mind. Did you get a ton of power with your mods? Also, what would you suggest for some beginning motor mods? Would a piston, cam, and rev box be worth the money? Thanks.

 

Wait on the rev limiter until you get the mods to hit the stock rev limiter. If i were you i'd start out by buying a JE standard bore piston. $100 Then a xr400 cam. $100 You'll be pretty happy with that. You'll get pretty big gain from a carb also, but i'd suggest getting it ported and polished when you do the carb mod.

 

Aaron10,

Would I still be happy with just the piston and cam for now? (Instead of getting it port & polished, and having the carb modded?) Also, what kind of power increase would I get? Does this help over the entire powerband and work well on the MX track? Thanks.

 

I'd say that your idle problem is because of your Lectron carb. I have one on my 400EX also and mine never idles right either. It's either too low or too high. Overall i'm not too impressed with the Lectron. I think i will be getting the 39mm FCR this summer.