PTO Kills Engine

[Mek-a-nik]

JD L130 with a Kohler CV23S 77769, about 11 years old.

I did maintenance work on it about a month ago. Owner mentioned that the engine dies when pulling the (electric) PTO. I found that it would not kill the engine if it was engaged at about 1/2 throttle (which is easier on the clutch, anyway). Then I found that the air filter was not installed correctly, and dirt had been entering the engine. The owner told me he takes it out occasionally to blow it out. I told him he was not installing it correctly, plus blowing out the element wasn't as good as a new filter because the pores clog. I told him his engine had most likely incurred excessive wear as a result.

Both spark plugs had good color, no dead cylinder.

Anyway, he called me over the weekend to tell me it's dying again when he pulls the PTO. I haven't returned his call yet, but I figure I'll check spark on both cylinders to be sure, and do leak down and compression tests.

Any other reasons it would die? I don't feel it's in the wiring, as it would stay running when pulled at 1/2 throttle.

EDIT: I just spoke with him. I told what I mentioned above, and said it's certainly possible that a safety switch is acting up since I was there working on it, and to make sure the mandrels and idler pullys are free. He said nothing is wrapped around the blades.

[HondaG100]

I found that it would not kill the engine if it was engaged at about 1/2 throttle (which is easier on the clutch, anyway). .

If compression checks okay I think you have a clogged low speed circuit in the carb. It becomes less important as the RPMs get higher. Does it idle well with the blades off? Most mowers (especially single cylinders) need at least a little power on to engage the blades so it may only be an imagined issue for this guy. I would also like to hear your reasoning behind high speed engagement being better for the clutch.

[bgsengine]

is he trying to engage PTO at idle or at full throttle? If at full throttle, Im with honda - idle circuit problem - (Can probably stall it out to or make it stumble if you snap throttle open when it is at high idle) if starting it at idle, it's probably a worn out engine - in fact most machines I rarely see them handle starting the PTO well when at idle.

[bobodu]

Had one do that...turned out the mounting bolts were loose causing a bad ground.

[Mek-a-nik]

I found that it would not kill the engine if it was engaged at about 1/2 throttle (which is easier on the clutch, anyway). .

If compression checks okay I think you have a clogged low speed circuit in the carb. It becomes less important as the RPMs get higher. Does it idle well with the blades off? Most mowers (especially single cylinders) need at least a little power on to engage the blades so it may only be an imagined issue for this guy. I would also like to hear your reasoning behind high speed engagement being better for the clutch.

As I recall, it idled fine. -It's been a while since I've been there. (I'm mobile.) I've seen that idle circuit problem, I don't think that's it on this one.

It's a twin.

I read in a manual for something, sometime, that engaging at 1/2 throttle, (not idle, it will die), is easier on the clutch itself. Less wear and stress.
But, I just read a MTD Cub Cadet manual that says engage at high speed. A single cyl., maybe as you said, it couldn't do it at a lower speed.

[Mek-a-nik]

is he trying to engage PTO at idle or at full throttle? If at full throttle, Im with honda - idle circuit problem - (Can probably stall it out to or make it stumble if you snap throttle open when it is at high idle) if starting it at idle, it's probably a worn out engine - in fact most machines I rarely see them handle starting the PTO well when at idle.

When I first went there, it would die engaging at full speed. I found that when running about 1/2 throttle, it would do it. He says now, that it won't even do that. I'm pretty sure it was idling good back then. Maybe it's not now?
I'll try snapping the throttle open.

[HondaG100]

Had one do that...turned out the mounting bolts were loose causing a bad ground.

That would be a tough one! Had an almost brand new Snapper in the other day with the engine already trying to escape.

[Mek-a-nik]

Had one do that...turned out the mounting bolts were loose causing a bad ground.

Good thought, too. I'll check.

[Mek-a-nik]

I don't go back there until next Wednesday. I'll report back...
Thanks for the ideas.

[KE4AVB]

Since it dying when engaging you really be there to listen to engine to see it is dying. A safety shutdown sounds different then an engine related shutdown.

When engaging the PTO. You need to remember that these engines run primary off the idle circuits when not under a load and used the main circuit when engaging any heavy load and the deck definitely qualifies as heavy. With this using a single barrel carburetor anything blocking the main circuit will show up in both cylinders.

BTW that engine number posted appears invalid as far as Kohler Plus look-up is concerned. It looks like is a CV23-75569