Export thread

6000 ZT Bogging down when PTO engaged.

#1

PTmowerMech

PTmowerMech

6000 ZT
S# BBZ6027K002102249
Kohler
M# SV840-3012
S# 4003614973

Major bogging when I engage the PTO. Cleaned out the fuel lines, drained some water from the tank and the carburetor bowl. Replace the fuel pump & filter. Got it starting and running way better.
When I engaged the blades, 80's of the time, it bogs way down. 20% of the time, it's normal.
All the idlers are fine. The spindle bearings sound dry. But there's no grease fittings. So they'll have to be replaced. But I don't think that has anything to do with the engine bogging, since the spindle bearings are still loose and turn freely. They're just noisy.

Top idle RPMs is reading 3000rpm. After the engine bogs then get's back up to speed, it does fine.


#2

PTmowerMech

PTmowerMech

Thinking deeper into this. could the carb still be needing a good cleaning? I noticed ever so often it wants to cough.


#3

B

bertsmobile1

prime suspect is one dead cylinder
I had 2 customers with mowers that had a dud cylinder from new and they never realised this till after I did a service and fixed the faults
They thought the engine bogging down when the PTO was engaged was normal .


#4

StarTech

StarTech

Yes it can be the carburetor as I had a CV680-3016 doing the very problem with a single barrel Keikin carburetor on an Exmark back in August this year..


#5

PTmowerMech

PTmowerMech

prime suspect is one dead cylinder
I had 2 customers with mowers that had a dud cylinder from new and they never realised this till after I did a service and fixed the faults
They thought the engine bogging down when the PTO was engaged was normal .

I took the RPM reading on both cylinders. Both read 3000.

When you say "dud," I'm guessing you mean it ain't getting any fire from the coil. Or are you talking about a valve issue?


#6

PTmowerMech

PTmowerMech

Yes it can be the carburetor as I had a CV680-3016 doing the very problem with a single barrel Keikin carburetor on an Exmark back in August this year..

I drove it around the garage to the back shop, where the lift is, and just for funzies, I engaged the PTO, and it didn't bog a bit. Tried it a couple more times, and was working fine. Then right before I pulled it into the bay, I pulled the button and it bogged so bad it almost died.


#7

PTmowerMech

PTmowerMech

Ok, so I've replaced all the contaminated fuel, rinsed out the carb and it's running better. It's not coughing anymore. Cranks easier. Changed the spindle bearings, rechecked all the idlers. And changed the plugs.
But still on first pull of the PTO button it still bogs down and dies.
Now, I can pull and push the PTO button quickly, let it get back up to speed (like 2 seconds) then repeat that a couple of times and all is well. But first couple of pulls on the PTO button, it's a no go.


#8

Hammermechanicman

Hammermechanicman

Engaging PTO at full throttle?


#9

PTmowerMech

PTmowerMech

Engaging PTO at full throttle?
Yes


#10

StarTech

StarTech

I took the RPM reading on both cylinders. Both read 3000.

When you say "dud," I'm guessing you mean it ain't getting any fire from the coil. Or are you talking about a valve issue?
Question are you doing this with the opposite cylinder plug wire disconnected at the time or with both plugs wires connected? If both connected then that just indicated that ignition is working but could still valve problem.


#11

Hammermechanicman

Hammermechanicman

Try disconnecting one spark plug and run engine at full throttle and engage and disengage the PTO many times then do the same with the other cylinder and see if there is a difference.
Also, when you engage the PTO and it bogs and dies try pulling the choke when it starts to bog and see if it revs back up.


#12

PTmowerMech

PTmowerMech

Question are you doing this with the opposite cylinder plug wire disconnected at the time or with both plugs wires connected? If both connected then that just indicated that ignition is working but could still valve problem.

Both plugs are connected when I take an RPM reading. And just to be sure the cylinder is firing, I read the temps from both exhaust. Both sides are hot.


#13

PTmowerMech

PTmowerMech

Try disconnecting one spark plug and run engine at full throttle and engage and disengage the PTO many times then do the same with the other cylinder and see if there is a difference.
Also, when you engage the PTO and it bogs and dies try pulling the choke when it starts to bog and see if it revs back up.

I think I've tried pulling the choke when engaging the PTO. There wasn't any difference, IIRC. But I'll do again, just to be sure.


#14

PTmowerMech

PTmowerMech

Starting and pulling the PTO with 1 spark plug disconnected.

But first cranking the engine with both plug wires attached, warming up the engine and pulling the PTO. It bogged down the first couple of times I did it. Even pushing the button back in, within a second, it would still die. After about the 3rd time, it would bog down some, but only at a normal level. And within a second, the RPMs came back up, blades were going like normal.
So then I disconnected one spark plug. Obviously only running on one cylinder. The problem is, I did this test after I'd already cranked the engine and got the PTO going. So pulling the PTO button, would bog the engine down more than normal (as in 2 cylinders) but it wasn't enough to kill the engine.


#15

Hammermechanicman

Hammermechanicman

I would let it all cool down an double check the deck spindles and idlers.
I would start engine and let it run full throttle for about 5 minutes to get wsrmed up then turn on PTO and see if it bogs


#16

PTmowerMech

PTmowerMech

I would let it all cool down an double check the deck spindles and idlers.
I would start engine and let it run full throttle for about 5 minutes to get wsrmed up then turn on PTO and see if it bogs

Yes sir, all the idlers check out.


Top