[HardcoreZ28]

Ok I'm having some serious headaches with the engine in my ride on mower and need some help. It's got a twin cylinder 20hp Briggs and Stratton in it. The engine is experiencing a major loss of power sporatically....but only when under the load of the blades. It'll start out ok and a few minutes in fall flat on it's face. Then if you limp it along it may come back full power a little later. When it does I notice a nice puff of black smoke usually. Sometimes it'll get so bad that it just won't run anymore in gear or with the blade engaged.

I replaced the fuel feed line and had the carb rebuilt by a local mower shop because I'm too busy to mess with it. The guy said there was a little dirt in it but nothing major. Replaced the needle and some seals. I put it back on yesterday and I'm still having the problem.

At this point I can only figure that I have some sort of ignition problem...but I figured that would be an all or nothing kind of issue...not come and go.

Any thoughts would be great. Anyone know how to test the magneto on one of these?? Coil??

Thanks