Engine Trouble Engine bogs down at top speed

[Martin]

I blew the end off of my stock Muffler by having an air ram attached to the carburetor intake.
Now running without the muffler cap the engine will reach its high RPM and then bog down. if I want to run the muffler this way are there some Simple Solutions to resolve this bogging issue?

 

[gary55]

I blew the end off of my stock Muffler by having an air ram attached to the carburetor intake.
Now running without the muffler cap the engine will reach its high RPM and then bog down. if I want to run the muffler this way are there some Simple Solutions to resolve this bogging issue?

Does it stop bogging when you hit a hill? show us a pic. of this ram air thing you got going on. If the bogging is due to 4 atroking it's a jetting issue. If it is slowing down then speeding up in a cycling repedative fashion with no change in throttle position it is a vibration/mounting issue.

 

[Greg58]

I've blew the end cap off and lost power, mine didn't have enough back pressure to keep the cylinder from purging . Like Gary said probably going to have to jet the carb, for me every exhaust change I have to tune the carb some.