Stuck cub motor

grandpa Love · Aug 17, 2021

Bought a cub in June. Motor is stuck. Was in a barn for many years, guy cleaned out the barn and pushed the cub outside,no cover on exhaust. Was out a few weeks. Took head off. Rust on 2 valves and piston #3 had a small trail of rust running down cylinder wall. Otherwise looks good. Stuck the shop vac in each cylinder and cleaned em out. Blew compressed air in around each piston. Filled with Deep Creep. Let sit. No movement after a couple weeks. Cleaned out again. Tried Free All. Nope. Tried transmission fluid. Nope. Starter is off. Rocked tractor back and forth,in gear,every couple days. Fluid drains down around 1-2-& 4. Tried pry bar on flywheel, tractor out of gear, very, very little give .......now what? Sure didn't look that stuck??? Am I missing something? We did buy a spare cub motor last week, at this point I just want to see this one turn.

SVcummins · Aug 17, 2021

Keep soaking

grandpa Love · Aug 17, 2021

Got nothing but time! I'm guessing the one that the fluid doesn't drain out is the stuck one??

Steve@Advance · Aug 17, 2021

If it's stuck that hard, might as well go into it.

Even if you get it running good chance it will have ring problems and do more damage than is already done.

smileykeith · Aug 17, 2021

take a block of wood and set on top of piston and rap with a hammer it will break loose

4520BW · Aug 17, 2021

I have used a price of wood and made a plate to hold pressure down on piston. I did that on a deere 70 and got it broke loose.

Mark-Ia · Aug 17, 2021

Hot boiling water helps expand things.

Tracy Brown · Aug 17, 2021

I have heard this, but never tried it. Put oil or diesel or your choice flamable liquid and set it on fire. This may have to be a soaked rag or something to act as a wick. The plan is to keep it burning a few hours The continued heat is supposed to expand the metal and in return, allow it to loosen. Sounds good anyway.

Geo-TH,In · Aug 17, 2021

My son uses a dilute solution of citric acid to soak rusty axe heads in over night.

I wonder what would happen if you put a little citric acid above pistons?
Think acid may remove some rust around rings??

If all else fails give it a try.

dzc3 · Aug 17, 2021

I have used brake fluid. I used air gun to blow out other fluids I had tried. Let is set of a couple of days and it turned over

old · Aug 17, 2021

Sounds like you have the head off. If you do fill the cylinders most of the way with ATF and then add a tablespoon of gas to each and light it up. When it burns out f you still have ATF in the cylinder add more gas and light it again. That heats up the block/sleeves so things tend to free up better. BTDT on a few of the touch ones

UncleTom · Aug 17, 2021

I am in the experimental mode with E-85. I would also try soaking it in E-85 just to see how good it works.

Jim in LA · Aug 17, 2021

Sounds like a procedure that must definitely be done OUTSIDE. Fire extinguisher at the ready. Safety!

old · Aug 17, 2021

Can be done inside if the roof is metal and far enough away. On a cub it is a good idea to have a flat piece of metal to cover the block if things start getting out of control.

560Dennis · Aug 17, 2021

Evapo-rust will get in there .

glennster · Aug 17, 2021

hey gramps, if you are not in a big hurry, put the tractor in 3 rd gear, jack the back end up and set it on a couple 2 x 10 ramps about 3 ft long and set em on a cinder block. then put the starting crank in, and if its in the right spot hang a 5 gallon bucket of rocks or iron to put a steady pull on it. you could also use a long pipe wrench and weight on the pto. keep your favorite penetrating oil on the pistons. if it is going to break loose, you will come out one day and the tractor will be at the bottom of the ramp. i did this not long ago on a super m. i did put pistons and sleeves in it, but it was way easier to take apart loose than locked up.

Steve A W · Aug 17, 2021

Watch this video on unsticking a motor.
It's by our own R. Aikin.
Unstick

T.R.K. · Aug 17, 2021

How about the valves? I bought a Cub 7-8 years ago that was stuck. it was really the valves and tappets that were stuck. I was able to get all the pistons out of the block (Intact, I think) but I broke the block around one of the tappets.

r aiken · Aug 17, 2021

That doesn't always work. I started on a rusted stuck H today and heating it up might not help this one.

old popper · Aug 17, 2021

I'll vouch for E-85. I used it to unstick a John Deere B that was stuck for years. That stuff eats rust.

Steve A W · Aug 18, 2021

I just watched the video.
You've got a job ahead of you with that one.

caterpillar guy · Aug 18, 2021

If you want it really stuck pour the acid in there. A friend of mine that is not mechanical was told to pour some draino or something like it down a 560D to get it loose he did and it didn't froze tighter than a winter day.

TomA in CA · Aug 18, 2021

Set a chunk of dry ice on each piston.

Stuck cub motor

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