OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines 725 EX mower hit old stump

new to this forum, was mowing for last time this year an hit an old stump, engine still starts with no heavy vibrations, starts and goes to normal rpm's then slowly dies, compression is 60 psi, im sure there are old posts about this subject but not having must luck with search feature
were would i start trouble shooting.

Give more details about the engine, model numbers etc, would be a good start as I personally have no idea what a 725EX is.

Its a 190cc (12 Cu In) Side valve (L-Head) engine. (120000 series) if My info is correct; although, the actual engine number will help.

I haven't never ran into that just dies slowly after hitting a stump. Most times it shears a flywheel key if not bending the crankshaft. I would be interested what the problem and solution is too.

got more numbers this am. 128M02 0943 F1 13041957 and yes 190cc from cowling
going to turn some wrenches now to try to look at flywheel key.

well my wheel puller kit doesn't have the right size bolts. and yes the key is cracked and just out of place. are the holes for the puller bolts fine thread, metric or standard?
never mind, got it off

i have one here same sticker on it , its on a FLYMO 20" . if it is the same its a quantum here in AUS' ?.

might have tried to start then died if it didnt break some fingers first . broken keyways will do it everytime .... but might be interesting to see if its all it was and if it vibrates more than before too ...... stumps done move much most times so bend stuff

Snookwon, Since you appear to be in the USA you might want to check out the following website too.

Professional Power Equipment Technicians and Education Network

well i put in new key and it would start, rev up and die quickly, then nothing for many pulls, then after 1 minute or 2, start,rev,die, guested fuel problem, removed carb, break cleaner all over it, poked all small holes with small wire, put carb back on, same thing, played with auto choke setup, runs normally now, no real exact answer to problem except key replacement