Low power after tune-up

[mjw357]

I have an Exmark zero-turn with Kawasaki FX801V engine. Brought it in the garage last fall, all was running perfectly. This winter I changed the oil and filter, fuel filter and the rocker cover gaskets because they were leaking a bit. While I had those off I figured I would check/set the valve clearance.


Went to mow this afternoon, started right up and let warm for a couple minutes before I started.


Wheeled over to the yard, half throttle, turned on PTO to start blades, full throttle. Seemed OK for a few seconds then lost power when I started moving. It just is not making full power/RPM’s with mower engaged.


What’s everyones first thought?

 

[bertsmobile1]

Double check those valve clearances.
good chance one has opened up & pushrod fallen off .

 

[Scrubcadet10]

Start it up and pull a spark plug wire off of a cylinder, one at a time. If it dies completely with one plug wire off, the other cylinder is dead,probably due to what bert said above.

 

[txmowman]

I have an Exmark zero-turn with Kawasaki FX801V engine. Brought it in the garage last fall, all was running perfectly. This winter I changed the oil and filter, fuel filter and the rocker cover gaskets because they were leaking a bit. While I had those off I figured I would check/set the valve clearance.


Went to mow this afternoon, started right up and let warm for a couple minutes before I started.


Wheeled over to the yard, half throttle, turned on PTO to start blades, full throttle. Seemed OK for a few seconds then lost power when I started moving. It just is not making full power/RPM’s with mower engaged.


What’s everyones first thought?

What did you set the valve lash to? Did you perform the adjustment properly?

 

[7394]

I'm leaning to valve lash set too tight.

 

[bertsmobile1]

Start it up and pull a spark plug wire off of a cylinder, one at a time. If it dies completely with one plug wire off, the other cylinder is dead,probably due to what bert said above.

I would be inclined to check the pushrods first as that is easy & cheap, if you used a gasket .
However those thin steel pushrods tend to vanish into the engine at the drop of a hat and then it becomes a big expensive job

 

[mjw357]

Each cylinder brought to TDC,

What did you set the valve lash to? Did you perform the adjustment properly?

Each cylinder brought to TDC, valve clearance set to 0.002" per manual found online. That sounded a bit tight to me, I thought it would be more like 0.004"-0.006".

 

[Tiger Small Engine]

Each cylinder brought to TDC,

Each cylinder brought to TDC, valve clearance set to 0.002" per manual found online. That sounded a bit tight to me, I thought it would be more like 0.004"-0.006".

Start mower and let warm up briefly. Spray water on each exhaust pipe and watch how it vaporizes. Pull the valve cover(s) accordingly and inspect. Something going on with the valves most likely.

 

[txmowman]

The service spec is .004” - .006”

 

[MParr]

Valve lash is too tight.