cm400 running lean on one cylinder

[Nathan81230]

Could use a little help with my cm400. It runs decent, acceleration is ok, top speed is about 80...eventually. I'm concerned about the left cylinder because it's running lean while the right is on the rich side. I have synced the carbs and checked for intake leaks. I'm fine with the way its running but I don't want to make it blow up. Any help/advice would be greatly appreciated.

Thanks
-Nate

 

[cxman]

have the carbs been apart and cleaned ?

have you check your intake boots for cracks or leaks at the orings on the head?

 

[Nathan81230]

I cleaned the carbs and the o-rings on the head are new. I sprayed starter fluid around the boots to see if there was a leak and it was fine.

 

[cxman]

has it been doing this since you rebuilt the carbs and did you remove the jets?

 

[cxman]

it is possible to both reverse the jets and completely mix them up within the same carb or from carb to carb

the stock jetting is 72/118

the 72 gets screwed directly into the carb body the 118 goes into the brass holder

make sure yours are arranged like this as its easy to mix up i see it all the time

and make sure the black rubber plug is over the slow jet hole or it will run rich

also check the choke butterflys for proper movement

 

[Nathan81230]

Thanks cxman. I'll check all that and see what happens.