No power

[Blackc2]

I have a scotts riding mower with a 17.5 ohv. This thing is about to get the best of me, it has no power. I have replaced carb, plug, filter, adjusted valves, replaced fuel filter, blown out fuel lines to ensure not clogged and checked valves to ensured not burned. After all this I still have no RPM but idles perfect. I don't know what else is left, any help would be appreciated. Oh pulled flywheel key not sheared.
I have also checked gov. It does go above idle a little but when you mow it just Boggs down

 

[ILENGINE]

First check the governor spring to make sure it is still attached. If that isn't the problem, then remove the valve cover, and spark plug, turn the engine over by hand and watch the valves. I have seen one of the cam lobes wear down to almost round, and it will act like the governor isn't working, even though the throttle butterfly is straight wide open.

 

[Blackc2]

Yea the governor appears to be operating as advertised and yes the buuterfly on carb can be wide open and the engine barely spools up. When hand cranken the flywheel the valves appear to be compressing and the mower does not backfire at all. The darn thing pures like a kitten at iddle. If I had not put a brand new Nikki carb on it, I would swear it was a fuel problem, I am ready to give up.

 

[ILENGINE]

Both valves are opening, but are they opening the same distance. the one that I worked on the intake valve would only open about 1/4 of what the exhaust opened.