07 scag stc61v-23bv slow down after about 30 minutes running.

[lizard62]

My scag tiger cub has the 23hp b&s vanguard engine. It seems after running mower for about a half hour or more , mower seem to slow down. I've changed the hydro fluid and filter. Plugs, air filter are all new. So if I shut it down and wait a little time , then restart it seem to be ok. But this seems to be happening everytime I use mower. Any suggestions will be much appreciated . Thanks

 

[bertsmobile1]

:welcome:

We are like Tommy the deaf dumb & blind pin ball wizzard
We rely totally on what you tell us and that is no where near enough.

Slows
Divers slower
Blades spin slower
engine turns slower

Does it change if you turn off the PTO ?

You know exactly what is happening but we don't

 

[lizard62]

:welcome:

We are like Tommy the deaf dumb & blind pin ball wizzard
We rely totally on what you tell us and that is no where near enough.

Slows
Divers slower
Blades spin slower
engine turns slower

Does it change if you turn off the PTO ? No

You know exactly what is happening but we don't

OK sorry about that , the engine slows down, I just don't know if its the hydro pumps causing it to slow down .

 

[577jersey]

Well lets see here,
The RPM on engine slows down,see if it slows down with PTO off and you sitting still with by pass valves pulled,,if so then I think your float bowl might be going dry or the governor is having issues..kinda hard to tell without seeing it in action...might also be the throttle cable creeping down on you.

Tom

 

[Mad Mackie]

Possibilities:
Fuel cap(s) not venting.
Fuel lines deteriorated internally slowing fuel flow.
Fuel tank transfer valve leaking internally.
Fuel pump starting to fail and or vent plugged.
Engine overheating due to dirty cooling fins.
Dirty air filter.
Dirt and or water in fuel system, check fuel filter.
Just a few!!!