Scag Cheetah Overheating

Valibertarian

LawnSite Member
Hopefully someone can help. I have a 2016 Scag cheetah with the Kohler 29 hp engine (Ecv860).

The engine wasn’t getting to full throttle and could barely kick in the blades so I replaced the spark plugs, changed the oil and filter cleaned the air filter and fuel filter. I also replaced the fuel shut off which was seized in one position.

That helped but then after about 30 minutes of run time, the Tiger Eye starts blinking all over and the engine begins to sputter and loses power. Still cuts but would bog down mulching or in taller grass.

Sounds like it’s misfiring and clearly is but I think it’s because it’s overheating. Runs fine for a bit every t

I can shut if off and restart and it will run and mow fine for a few minutes.

When I check for error codes, I’m getting the “Lean fuel condition under load” series of error codes.

I was thinking maybe the oil cooler is clogged but I can’t even find it on my Scag.

There’s a possibility that a relative who was using it filled the gas with a oil/fuel mix for my blower.

I’ve cycled through all of the fuel so no bad gas remaining.

If you guys have any thoughts I’d really appreciate it. I’d take it to my dealer, but he’s a dick and I know it will take five trips to get it right.
 

VegetiveSteam

LawnSite Senior Member
Location
St Louis, MO
What was the actually code number? Try this. Unplug the O2 sensor and see if it runs any better. It's not going to hurt a thing so be sure and run it long enough to where it would normally act up. If it does run better then we know something is causing the O2 sensor to give bad info to the engine computer. It could be because the sensor is bad or something fooling the O2 sensor into thinking something that isn't actually true. For instance. A hole rusted in the exhaust system lets in oxygen that shouldn't be there. That oxygen can fool the O2 sensor into thinking the fuel mixture is lean when if fact it isn't. It's sensing the oxygen that is getting in through that hole that isn't supposed to be there. The O2 sensor then tells the computer to add more fuel. Normally if that happens the engine runs rich and will blow some black smoke. That will make you scratch your head because you are getting a code saying it is lean but you can see the black smoke which proves it isn't lean. And BTW, Scag didn't spec that engine with an oil cooler so you can stop looking for it. It's not there. :)
 

VegetiveSteam

LawnSite Senior Member
Location
St Louis, MO
If unplugging the O2 sensor makes no difference you should check the fuel pressure which is critical on an EFI. It needs to be a minimum of 36 psi.
 
OP
V

Valibertarian

LawnSite Member
Fuel is flowing. I’ll check the O2 Sensor. Not a ton of smoke when it acts up but it’s intermittent. Will check the pressure as well. Given the cut off valve seized, I’m thinking something is going on with the fuel.
 

Top Forums



Top