Ariens Zoom 1740 / Kohler 17hp - engine seized up

Have a Ariens zoom 1740 Zero Turn I obtained use a few years ago. Engine seized up on me the other day while finishing the backyard. it was very hot (near 100) and I figured it just overheated as ran fine for a couple hours. Oil level was fine the previous weekend, but looks like it just burnt some up when I pushed it back in the garage and checked - smoke from oil stick.

I drained the oil, and tried PB Blaster in the cylinder to see if I could free it up, but no luck. I had quite a bit of leverage, and would not spin or budge either direction.

Anything I could look at first to start tearing it apart to see what the problem ultimately might be?

ariens 915067

If there was no oil in the engine, it is toast and you are wasting your time trying to fix it.
The piston seizes in the bore and damages both the piston & the bore.
Then the conrod usually bends and the engine seizes on the top "bush" which is just a hole in the alloy case.
If it is a courage the top plate can be replaced along with the piston & rod.
If it is a Command engine then you will need a new short block.
Home machinists will pay a reasonable amount seized engines as they will pull them down & put a bush in the cases for something to do in the shed.
Machine shops will charge nearly as much as a new short block.

It is very rare to be able to recover from a full seizure economically.
And we have not even touched upon where all the oil went and the fix for that.

Bad news , sorry about that but it will be a case of good money after bad, unless you are looking for a quality time father/son project.

Measure the PTO shaft then go to a discount surplus engine vendor
SES , SEW, Surplus Center etc etc ( some are in the sponsors section of this site ) and get a replacement engine.
If you go with a Kohler, just pick the cheapest with the same PTO shaft size and the same or higher Hp as all the acillary bits like alternators, carbs, control plates will transfer over if they are not the same.
Some times with 2 almost identical engines one will be 1/2 the price of the other

I think it is a courage from what I have seen, so looks to be able to take the top plate off to see what may have happened inside.

Core2 said:

I think it is a courage from what I have seen, so looks to be able to take the top plate off to see what may have happened inside.

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Better than average chance that the top plate will be locked solid onto the crank.
If so you can pry out the oil seal and brush some pool acid ( HCl) slowly on the shaft to clean off the melted alloy.
Before you start note if the front 4 bolts ( near the cylinder ) are loose.
If so check for a crack in the case running down from the top plate near the exhaust cam.
This is fairly well a terminal failure.

No cracks in the case that I have found. No bolts were loose.

Motor is sv530s - top plate stamped 20-499-01 CAV 2

I started pulling it apart today, as it's the 4th and I was off anyways. I was able to remove the end cap off the connecting rod, and the piston can move - was not stuck. However the crank will not move at all.

I am guessing whatever seized up, it is the bottom of the case holding the crank. I assume I should be able to simply pull it up and out of the case somewhat easily, but it acts like it's a solid part and not budging.

(Yes, clutch is off)

You must have been a very good boy in a previous life. :laughing:

Every thing pulls directly up.
usually they seize on the top bearing as it runs out of oil first.
I am assuming the con rod has already been removed and pushed up in the bore right out of the way
before you use forcus extreamus on the crank, get under the engine with a wire brush on a drill , Dremel etc and give the PTO end of the crank a good clean.
make sure there are no burrs or nicks, file if necessary , then lube the shaft, put a jack under the crank and push it out

I do have the rod out of the way, and I had a jack under it - but decided to hold off on my gut decision to get more input. I have been going over the manual I ran across (http://www.kohlerengines.com/onlinecatalog/pdf/sm_20_690_01.pdf)
Just to make sure I did not miss a bolt, or another part holding the crank in place.

I actually took 1/2 the balance weight off as was not sure if that was keeping something contained......

"Oil level was fine the previous weekend, but-----------"

Wow, I never start either mower before I check the oil first.

7394 said:

"Oil level was fine the previous weekend, but-----------"

Wow, I never start either mower before I check the oil first.

Click to expand...

But.... it still had plenty of oil I drained out of it. was not dry.

I can't get this crank out of the case. I have a jack right under the shaft, back 2 tires are 1/2" off the ground + I am standing on the frame tapping with a rubber mallet.

I have a time bit of side to side wiggle from the crank, but I think that is just wiggle room with the old seal.

I assume the seals install from the bottom (outside of the case)? I am thinking the shaft is really stuck to the seal as just won't budge.

Can I try cutting/digging away at the seal perhaps? Is there anything else that might be keeping the crank stuck in the case?

EDIT:
After a bit, I am able to slowly rotate the crankshaft 180o from 3oClock to 9oClock position with some effort. but still, it just does not come out.

Am I neglecting something holding the crank in place?