400F problem.

wilber551

dirt/street
You've all been very helpfull with my 400f build. Its complete now but I'm still having the same problem as before. I'm at my wits ends. I've had the engine bored to a 466. Before the rebuild the bike ran great, no smoke just a siezed cam chain tensioner. I had it jetted perfect then BOOM. after the build I can't get it to run correctly. I've checked the timing.. its spot on. I've got good compression. I adjusted the floats for less fuel. I have stock jets installed. I had the electronic ignition timed correctly. Even before I installed the hotter coils and ignition the bike did the same thing. Basicly bubbling fuel out the exhaust. It smokes like a mother on the accel of the throttle. But nothing on decel. I never split the lowerblock. Just rebuilt the top end. I'm not burning any oil. Im going crazy trying to figure this out. Does anyone have suggestions?
 
It should be lean with stock jetting.
Have you checked carbs are not flooding and all the vents are clear?
I would say you have multiple issues.
Carbs will need cleaning out again
 
I did check my carbs yesterday. I adjusted the floats so there's less fuel in the
bowls and all it did was bog the engine down bad. Felt like I was pulling a trailer
 
I'm still thinking when you reassembled that motor you've got the cam timing off (off a tooth or more on the cam sprocket). It would look like its in time (ignition timing), but the valve timing would be way off. Just an educated guess.

Also, how are your compression numbers?
 
I remember you asking me that before about the timing, I did adjust it back one tooth and foreword to.check and it did run worse when I moved it so I know the cam timing is set. I don't have the compression numbers, but I will soon. I broke down and took her to someone who knows there shit. I'm heartbroken loll but I will ride this bike this season!
 
Did you end up figuring out what was wrong with this? .. Sorry for bringing back and old thread but figured I would ask here instead of starting a new one as I have a similar issue.
 
Glad it got brought back, had another think about it and it sounds like the piston rings were fitted upside down and possibly in the wrong grooves
That would give a lot of smoke
 
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