Revving and bogging

[neiltannis]

Hey there motor bikers!! Happy new year and all that jazz. I'm banging my head against the wall here on my 3rd build. Starts up great when fully choked, but begins to rev like crazy when choke is switched off. The engine also bogs when throttle is turned. I can't find any air leaks, carb float looks good, outside temp is about 42 degrees. Any ideas would be greatly appreciated.

 

[Greg58]

I would first check the barrel to make sure it is traveling all the way to the idle screw, I’ve had warped carbs before. Look around the base of the cylinder, case half’s and at each seal on either end of the crankshaft, the seal behind the rotor is the worst to leak. If you find any fuel in any of these areas you’ve found your leak.

 

[Greg58]

Just wondering, why are you running the offset intake? Looks like plenty of room for a straight or stock type. With the weight of the carb and filter on the intake that could be a air leak also.

 

[neiltannis]

Thanks a lot for the tips! Before when I tried to use the stock intake with that filter it wouldn't fit, but now I changed the alignment, so it might. This is the first time I have used the offset, and that's where I was thinking the problem might be also.

 

[Greg58]

I would try the stock intake and filter to eliminate or prove the intake leak.