A friend gave me his well used, poorly maintained Ryobi trimmer. Its the one that you can swap out multiple attachments with one power head. Starts up fine, but it will not reach full throttle, hovers ever so slightly just below max. If I remove the muffler, it reaches full throttle immediately. So, getting a little back pressure from the muffler which is caked full of carbon. How do I remove the carbon deposits to try to achieve full power. Carb. cleaner didn't touch it. Looks like the throttle body is set to full open.

New to this forum. I've searched and read several threads about this but I need help for my specific problem. Item: Craftsman Mid-Engine Electric Start 30" Mower/Mulcher Hydrostatic Drive model 5363.270320 (Riding mower) Engine: Briggs & Stratton model 21B807-3026-E1 Problem: Flywheel turns but engine won't start. Started acting up in beginning of season with intermittent stalling. Now no longer stats at all. Having read previous posts I'm almost convinced the flywheel key is sheared (item 24 p/n 222698s). I've got gas in the carb and the fuel solenoid is operational. I'm quite sure I'm getting spark. My problem is getting the flywheel off. The plastic fan on top of the flywheel is held on with a bolt (not a nut). How do I prevent the fly wheel from rotating? I noticed an approximately 3/8" dia hole in the side of geared flywheel that is exposed as if a steel rod can be used to insert and hold as a counter pry against the socket wrench. But, I have no place to wedge the rod against. Is this is what that hole is for? Can I get a helper to hold the bar while I try to loosen the bolt? Or is that hole just a machined hole to balance the flywheel? Since I'm not absolutely convinced that the key is sheared I'm reluctant to buy special tools that I'll never used again.