Need tips on how to pull a pny motor on 720

chas036

Member
I am trying to replace my water pump on my 720 pony motor. I ended up cutting the bypass pipe and the inside bolt in order to get the cap off, but I can see that there is no way the inside bolt will go back in without pulling the engine to clear the governor.

I have never done this before, so I would like some guidance on how to do it, like what bolts need to be removed etc. I already have the steering arm off and the tractor sits under a beam in my barn.

What do you attach the chain too on the pony motor to pull it?

Do I have to remove the starter, or can that be left in place?

How do you remove the exhaust pipe?

Does the instrument dash need to be removed?

What gasket do I need to purchase before I reinstall the motor?

Can I cut that little pipe between the water pump and block? I don't see another way to remove the pump. It won't budge a bit with that pipe.
 
I have the service manual, but I am looking for some tips that are not in the manual from people who have done this, like how do you remove that small water pump pipe?
 
Been many years ago I pulled one but I do know that none of the pipes need to be cut. I'm sure the jd service manual gives detail instructions and illustrations too.
 
It's been a few years since I did my 70 and 80 so I'm going off of bad memory. I do have an 80 pony to screw with soon...

There are four big bolts holding the engine onto the top of the tractor, plus usually two more small ones though the flywheel cover.

Disconnect the engagement linkages, gas line.

Removing the starter probably isn't necessary but gives a bit more wiggle room.

The exhaust pipe, you'll have to loosen the pony and slide it back enough to get the pipe out of the manifold, before lifting, if I remember right.

For hoisting, it's been a while but I think I used the top two bolts between the block and the clutch housing. It doesn't balance with those, but they're sturdy

The water pipes can be a pain, they're only held in with O rings but after 50 odd years of corrosion they tend to get really stuck. The only thing I can suggest is wigging the pipe as much as you can, especially with a twisting motion to try to break it loose. Heat would help too, on the castings that the pipe enters, to try to break the crud and hardened rubber loose. I'd hate to cut the little pipe, it'd be hard to get the right length without a lot of trial and error, I think?

Brandon
 
chas036,

This is how I do it. A shop crane (engine hoist) on wheels works great even in my crowded barn.
Do not destroy anything you don't have a replacement for, you will be sorry.
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After removing the water pump in the 80's pony because of grey colored oil in the pony while cleaning the bottom of the pony crank case I found these pieces of ring from the pony pistons. This pony started great and ran strong with lots of smoke. I predict you will find something similar as contrary to talk on this forum, that water pump you are pursuing is rarely the cause of your problem. The guys from "foreverdeer" will tell you those rings are the weak link and an upgrade they put in their rebuilt pony motors. I have received this info from more than one professional in this area of service. You may need to do as I did and just get a good rebuilt mmotor.
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Thanks for all the advice. Do you think the two carburator studs on top of the manifold are strong enough to use as attachment to pull the engine?

Where are the shims located? I hear alot about these.
 
They are under the two bolts on the trans. side of the motor(could be more or other side on yours). Here they are and what they look like.
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Actually they are under the locator pins next to the bolts. GOOD LUCK with this problem, be safe, and do as little harm as possible as you go.

Dan
 
Dan, I saw you had the transmission removed, is it easier to pull the engine by first removing the transmission , or can you raise it with the transmission in place? I don't need to remove it from the tractor, I only need to raise it sufficient to install the new water pump.

I am having a problem removing the main water pipe, so I was wondering if I just cut a section out of that water pipe and then when I reinstall the motor, I connect the two ends of the pipes with a rubber hose and clamps. It is not original, bit you think that would work?
 
When working on the 70D I only needed to raise pony enough to get the trans/clutch assembly off over the diesel fly wheel. I absolutely would NOT cut that pipe as you should not have to, it is only held in by o-rings. Try softening them with PB blaster and keep working at moving the pipe, it will move. Leave the trans alone and remember, do as little harm as possible. Was thinking I used a home made tool like ratchet strap to wrap around the pipe to get it to move. Plumbers use a similar tool to remove filters from drinking water systems.
By all means put away your tubing cutter. Keep working at it using PBblaster, once it moves a little it will come out.
 

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