# Craftsman power loss when pto engaged



## bhanecak

I bought a GT5000 used and the previous owner stated there was an issue with the electric pto clutch. The issue remains that when the deck is engaged, the engine wants to stall and will barely remain running. It will mow, but will bog down even on the slightest incline. I read many posts on this site and several other sites to diagnose the problem. 

My first thought was to check the gap in the clutch itself. I adjusted it to the specified .012". Same issue.

I then checked to see if it actually "clicked" when the pto switch was pulled with the ignition ON, but not the engine. It did click like it is supposed to.

I pulled the belt off the clutch and used the belt to spin the blades. The blades spun with relative ease (as they should since I just rebuilt the deck and mandrels.)

I took the clutch off the engine and ran the same test with the ignition on and the pto switch pulled. The clutch clicked and spun freely, as it should. With the pto off, the internal brake takes over, again as it should.

I checked the resistance in the unit itself and it registered 3.5 ohms, which I think is OK.

I started the engine and pulled the pto (with the clutch still off the engine) and it again spun freely (as it should) but it had no effect on the engine bogging down like it did attached.

I reinstalled the clutch back onto the engine and ran the test above. The clutch DID spin (as it should) but did not effect the engine again. 

At this point, I am thinking things are good to go. So I installed the mower deck and belt and tried again. I started the engine and pulled the pto.....again the engine almost died trying to keep the mower blades moving. 

I also just got done rebuilding the carburetor due to engine running rough, even without the mower deck not engaged.

I was told it might be the governor, so while the engine was running I played with the lever and it automatically regulated itself back to normal. I'm not sure if that means it is working or not, but it seemed to. 

I was hoping someone on this forum has anymore suggestions. 

Thanks in advance,
Brian


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## Bill Kapaun

My guess is you have a weak cylinder.
Pull and ground one plug wirees at a time.
If one side kills the engine and the other shows little difference, guess what!
IF it appears one cylinder is bad, pull the valve cover on that cylinder and observe the obvious.


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## bhanecak

Bill,

Your theory is similar to others I found on the internet. I borrowed a compression gauge from a guy at work and decided to give it a try. The first clue something was wrong was one spark plug was warm from running the engine, the other was very hot. The hot side registered a 155psi and the warm side was only at 45psi. Your theory was correct!!!!

I decided to continue to take your advice and I took the valve cover off. The rod that connects the back of the valve rocker arm (I think that is what it is called) was just laying in there. We tried to put it back on but the valve was so sticky that the spring couldn't pull it back into place. 

So the conclusion is I have a valve that is probably gunked up inside. I'll need to take the head off and clean everything up. Is there anything else I should check or replace while I am in there?

Thanks again for putting me on the right path.

Bri


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## Bill Kapaun

Before removing the head, you might try a good solvent like PB Blaster, Liquid Wrench or similar.

Spray it liberally around the valve stem and try to "work" the valve a bit. Let soak, repeat a few times.

I fear you my have actually bent the valve though.
Examine the valve guide and see if it has actually moved, preventing the valve from functioning correctly.
Compare to the other cylinder.
You "might" end up having to replacie the head. I think that still might be cheaper than a new PTO?

Also check for a bent push rod, or wear on the side of the PR where it may make contact. Supposedly, you can swap the PR end for end, if it's showing wear.


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## HYDROGUARDIAN16

bill, are you the owner of Bill's power center? lol just curious


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## Bill Kapaun

> _Originally posted by HYDROGUARDIAN16 _
> *bill, are you the owner of Bill's power center? lol just curious *


Nope????


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## HYDROGUARDIAN16

his last name is different


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## dman12

Maybe you have 1 bad ignition module and are only running on 1 cylinder. I had same issue.


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## Bill Kapaun

dman12 said:


> Maybe you have 1 bad ignition module and are only running on 1 cylinder. I had same issue.


I doubt they would suffer through this for 6 years!
You might look at the DATE of a post....


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## dman12

Bill---I did realize the date! But if someone like me does a search and is looking for an answer they might see my response and it will help them out. I searched high and low looking for answers reading old and new threads.

And yes I agree that I doubt they suffered thru this for 6 years.....have a great day.


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