hey everyone. I have a 48" Toro grand stand mower that stopped running yesterday. I got it back to the shop and checked fuel, spark, condition of the plugs. the plugs were black and sooty. i checked compression and got 1 cylinder with 90psi and the other with 180psi. I have no odd noises in the engine it moves freely. valve train seems to all be moving properly and in adjustment. not a 100% sure where I should go next. any help would be appreciated. thx in advance.