782 lack of power under load
 

Afternoon everyone wondering if I can get some ideas. Got a little bit of seat time today with my new 1861, which ran better (and worse) than expected, but decided I wanted to finish the job up with the 782. Anyway I ran it out to the grass, fired up the pto, and then went to throttle it up, and it wouldn't hit WOT......stumbled/stuttered and just couldn't recover. It was very odd, I really couldn't tell if it was a fuel stutter or ignition. Regardless I'm here to see if anyone can shoot me some ideas. The tractor was NOT hot at the time and it starts easily. I rebuilt the carb a few months ago, and my gas is relatively fresh (last few weeks). Its really strange, the ride back was smooth and didn't seem to have any issue, just when I'd hit the PTO it just wouldn't come up more than about 1/2 throttle. I cut my yard with it yesterday and didn't have any trouble at all. Help!

Bcdsfcret
 

One of my 782s did that and I found the wires on the coil were bad. The spark plug wires were burnt on the coil end. You may have to clean up the coil and replace the spark plug wires. I did that on mine and it cured the problem.
Brian
:American Flag 1:

Sounds to me like an ignition problem. Under load higher voltage is required to jump the spark plug gap. Several things can cause the symptoms you are describing. Faulty spark plugs and or wires, defective coil, defective condenser, or even points that need to be cleaned or replaced. From your description, I would start with checking that the plugs are not fouled. The higher the voltage that is required to jump the gap, the more it is going to "seek" a shortcut to ground. A carbon trail on a plug or a faulty wire can do that. Points and condenser can also do that, but are not so sensitive to the load of the engine. A coil can also do that, but usually don't show symptoms till the coil heats up. Start with plugs and wires.

If you just cut grass with the tractor the day before and it was fine. I'm pretty sure it didn't suddenly foul the plugs. Let's rule that out. Also because it runs fine when the PTO is not on.
Probably not bad fuel..... for the same reasons.
Probably not a bad plug wire....... for the same reasons.

We're looking for something that can/did fail suddenly. Probably a bad wire/connection to the coil.

Questions:
Does it run WOT without the PTO on?
How easy does it start?
When you say it wouldn't reach WOT, did it sound as if it is under load? Perhaps it isn't a motor problem at all. A bad bearing in a spindle, or one of the mule drive pulleys would do it. Could also be something wrapped around the blades.

Go fire it up. Warm it up and see if it will run WOT without the PTO. If it will, kick it on and try it again. If it peters out, take the deck drive belt off, then turn the PTO on again. Now how does it act? Go drive it around and move the hydro lever really fast to load the motor. Now how does it act?

There is a chance this isn't an engine problem at all. :bigthink::bigthink:

Good way to put it under load is chain it to a tree or truck hitch or something.