exhaust problems

[brtractor]

i have a Briggs and stratton 18,5 hp single cylinder vertical shaft engine on a jd zero turn . was having problems with loss of power then the carburetor started acting up. i replace it as well as the new coil plug etc. checked timing valve clearance , push-rods are straight, compression checked out just fine. with the new carburetor same things not as bad but a lot of exhaust coming out of intake (carb). i checked valves a lot more thorough and it seems the exhaust isnt opening up all the way ( just my opinion).
what would be causing this and what is the fix for it. any help would be greatly appreciated.
thankyou
brian

 

[Fish]

Take off the valve cover, and rotate the engine by hand, and watch the rocker arms. See if the rocker arms are both moving the same amount of travel. You may have a badly worn cam lobe.

 

[brtractor]

Take off the valve cover, and rotate the engine by hand, and watch the rocker arms. See if the rocker arms are both moving the same amount of travel. You may have a badly worn cam lobe.

Thanks did just that and exhaust side does not open as much as the other Side . Gonna take head off and get a rebuild kit for it

 

[slomo]

Might check the camshaft while you are at it. Or the exhaust valve might be sticking half way open.

slomo

 

[Scrubcadet10]

Thanks did just that and exhaust side does not open as much as the other Side . Gonna take head off and get a rebuild kit for it

Did you rotate it several revolutions? Just to be sure it wasn't the ACR bumping the valve open.

 

[Fish]

Yeah, if you have a bad cam, you would have to tear it completely down. Can you take a video of the rocker arms, while you rotate the flywheel 2 full revolutions? With the plug out, I mean.
That is why the exhaust would be coming out of the intake, if the exhaust lobe was wiped out.