compression issue

Racerrick72

LawnSite Member
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.
 

Valk

LawnSite Platinum Member
Location
KS
Kaw engine? Have you kept the cooling fins cleaned out/free of debris/etc over the years...? Valves adjusted to spec?

Could be oil getting by rings (or valve guides?).

Replace sooty spark plug w/ a freshie and see what happens.

Toward the end of life of my old Kaw FH, I removed and cleaned the spark plug every other day w/ a wire brush. Only takes a couple minutes and made a huge difference.
 
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Racerrick72

LawnSite Member
yes kawasaki engine sorry I didn't state that. If in getting oil by the rings or valve guides id get smoke from exhaust wouldn't I? Also would that cause the big difference in compression?
 

hal

LawnSite Fanatic
Location
Georgia
How many hours? Put some oil in the low cylinder and see if it pops up a bit.
 
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Racerrick72

LawnSite Member
I just found the issue. Now to figure out why it did this. Not sure how I missed this yesterday but found a bent push rod on the higher compression side of the motor.
thank you for the feed back it's much appreciated.
 

douglee25

LawnSite Senior Member
Location
TX
Valve could be sticking on that side of the motor or the pushrod just came out of location. Although rare, I have seen that before. Take a piece of wood and use a hammer on top of the valve. Make sure it moves. Put another pushrod in there and give it a go.
 

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