engine dies when PTO is engaged

[freewheel3]

deck is turning free, all pulleys are fine, engine is not reving up when PTO is engaged

We're going around in a circle here and its back to sounding like a fuel delivery problem. Since you had to "clean the fuel system" twice, maybe its clogged up again. I'd check that.

 

[Eric McCarthy]

If the engine is running fine all day every day then dies when the pto is turn on, its not a fuel delivery issue. Its either the electric pto or the switch is gone bad. Same exact thing happened to my Toro Proline walkbehind. The switch went out, it didn't supply enough current to engage the pto and could kill the engine because it struggled to spin the pto.

 

[freewheel3]

If the engine is running fine all day every day then dies when the pto is turn on, its not a fuel delivery issue. Its either the electric pto or the switch is gone bad. Same exact thing happened to my Toro Proline walkbehind. The switch went out, it didn't supply enough current to engage the pto and could kill the engine because it struggled to spin the pto.

Huh? How does a pto not engaging cause an engine to power out and die? Im lost here.

 

[Eric McCarthy]

The engine has to be able to power the load, if the electric pto is going bad or if the switch is faulty and not engaging like it should then the engine is trying to work harder to power everything and dies. The deck drive belt wraps around the pto, the engine transfers power from a shaft to the pto clutch then out do the belt then the blades.

Basically the engine is stalling out because it can not turn the electric pto. The pto itself or the switch to engage it is going bad.

 

[cyclehd]

We're going around in a circle here and its back to sounding like a fuel delivery problem. Since you had to "clean the fuel system" twice, maybe its clogged up again. I'd check that.

I didn't have to clean it I was thinking it was a fuel delivery problem, but I never found anything it was spotless. Even cleaned the gas tank. No dirt. Clean. What about the govener not spooling the engine up when I engage the pto?

 

[Eric McCarthy]

The governor just put a limit to how fast the engine will go. It as no affect what so ever on spooling the engine. It just allows the rpms to reach a set rpm and wont go past it.

 

[Bulldog]

I can engage the pto on mom's JD at low idle and it doesn't kill the engine. In fact from what I have found if you want the eletric pto clutch to last it needs to be engaged at low idle to help keep from burning the clutch out. The engine shouldn't need to be running wide open just to power the deck.

 

[freewheel3]

I didn't have to clean it I was thinking it was a fuel delivery problem, but I never found anything it was spotless. Even cleaned the gas tank. No dirt. Clean. What about the govener not spooling the engine up when I engage the pto?

Post a video. Maybe it'll give us all a clearer understanding of what's going on here.

 

[skeets]

Ok so if I have this right,,,, with out the mower deck the tractor runs fine,, now engaging the PTO with out the mower is not a problem am I right so far? Now engaging the mower deck the motor stalls,, right?
I think that maybe I would look at the mower deck gearbox,, just MHO

 

[cyclehd]

What's the easy way to send video using an iPhone ?

 

[Eric McCarthy]

I can engage the pto on mom's JD at low idle and it doesn't kill the engine. In fact from what I have found if you want the eletric pto clutch to last it needs to be engaged at low idle to help keep from burning the clutch out. The engine shouldn't need to be running wide open just to power the deck.

Give the right size engine and deck combination your right. I have a 14hp Kohler motor on a 44 inch deck on my Toro Proline and I have to have the engine throttled up before I can turn on the pto otherwise it'll just stall out.

Even your method can be a tricky situation, if you start the mower up in thin grass or on a hard surface it works.

 

[Bulldog]

Good point, didn't think about sitting in tall grass.

If it keeps raining here I'm going to be mowing the yard with the batwing again.

 

[Bulldog]

Ok so if I have this right,,,, with out the mower deck the tractor runs fine,, now engaging the PTO with out the mower is not a problem am I right so far? Now engaging the mower deck the motor stalls,, right?
I think that maybe I would look at the mower deck gearbox,, just MHO

That's what I thought to but early on in the post he said the deck turns freely. Don't know about y'all but this one has me stumped.

 

[cyclehd]

Post a video. Maybe it'll give us all a clearer understanding of what's going on here.

Here's my email cyclehd@hotmail.com drop a line ill send you the video

 

[Bulldog]

Your mower sounds bad. My first impression is that the deck is binding up but I know you said it turns freely. I guess the next step is the pto clutch itself. I still don't understand how the clutch slipping can kill the engine but I'm not a mechanic either. Good luck and keep us posted.

 

[Eric McCarthy]

An electric clutch can be a funny tricky thing. Sometimes they don't out right die and stop working. They linger for a while and work half assed. I've replaced many of them through out the years. Its a simple replacement.

 

[uglyboy]

I didn't have to clean it I was thinking it was a fuel delivery problem, but I never found anything it was spotless. Even cleaned the gas tank. No dirt. Clean. What about the govener not spooling the engine up when I engage the pto?

cyclehd... you've asked a couple times about how does the governor spool up the engine when the PTO is engaged... are you saying the throttle does not get the engine running fast ?
while the throttle (left side of steering wheel) controls the engine speed... when additional load, like engaging the PTO, is applied, the governor essentially opens the throttle plate in the carb a bit more to try to maintain engine speed under the increased load. If you've had the carb and or throttle linkage plate beside the carb off, maybe the linkage was put back together wrong.
another way to apply a sudden load is to open the throttle to get the engine running at a medium to high speed, then mash the HST pedal... if the engine does not try to maintain rpms, then you may have a governor problem.

Pete

 

[skeets]

This may not be a part of the problem, but I stopped to see an old hotrod buddy yesterday, he has a new butoa in the garage and was not real happy with it, its a gas mower and was doing the same thing stalling when the mower was started. Now his wife works at the local butoa dealer so of course they came right down,, to make a long story short the dealer replaced the fuel delivery system with an older type of I think he said from an 05. The dealer told him that the mower pulls so much off the motor on start up the fuel delivery system cannot keep up and so it stalls. He says it works really good now but is one thirsty SOB.

 

[cyclehd]

Thanks. I did just that and it spooled up just fine

 

[Eric McCarthy]

Same thing I've been saying all along, I say the pto clutch is going.