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?
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
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.
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......
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#8
7394
"Oil level was fine the previous weekend, but-----------"
Wow, I never start either mower before I check the oil first.
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?
Motor is done. Pulled the motor out of the mower, and took it to my in-laws auto shop. Could not get crank out, so tried to press it as done for anyways.
Well.
Sort of explains why it would not come out.
Degrease the crank then treat it with HCl to remove the welded on alloy.
Then measure the crank carefully, no use buying a short block if the crank is toast
If your mate has a mill & lathe consider a bronze bush in the case if the rest if the short block is in good nick.
Get the end of the barrel cleaned up with a ridge reamer to remove the carbon lip at the top of the bore and turn up a bush in LG 2 ( 85 Cu- 5 Sn- 5 Zn-5 Pb ).
Never had a bottom bush go before, usually the top.
You can usually get a superseeded / surplus engine from SES or SEW or Surplus center for less than a new short block.
Depends upon your pocket and weather your time or your wallet are the most under pressure.
Several Kohlers that will fit in the $ 600- $ 700 range
You should be able to get around $ 100 to $ 200 for your old engine because there are a lot of home machinist that will weld & machine or make a bush then resell the engine going.
It does not have to be the exact same engine so you could fit one of the twin scratch & dent engines .
These will either be insurance claims of damaged in transit or manufacturer pulls .
I bought 2 pallet loads of pulls last season.
If you go to Briggs then it gets a lot cheaper
There are complete Inteks for less than the Kohler short block and they will mechanically drop strait in
#17
7394
Bert- So "Short blocks" do NOT have the crank in them ? Then no pistons either. Yes ?
In the auto world, short block is complete with pistons, just NO heads or accessories.
According to Kohler
A short block is as you imagined
You will need to swap your altenator, flywheel, rectifier. starter motor fan , blower housings pushrods & head
Some come with the sump ( or top plate in your case ) some don't
A mini- block is supposed to be the same minus the crank.
However more than once I ordered a short block & got a mini block.
A lot of vendors do not seem to know the difference.
I have a good lathe & the landlord has a massive mill ( 1939 Addcock & Shipley No 19 ) can cut 1" deep x 10" wide.
We use it for boring as it is better than a lot of boring machines.
Thus if the rest of the case is good, I mill the old bush area and fit a LG 2 one machined to suit the crank.
The first couple we did we line bored to make sure the top & bottom bushes were in alignment bit we found, indexing off the crankcase joint face was good enough, except for a racing engine
$ 40 for grinding the crank ( per journal ) and $ 20 worth of bronze.
I send the cranks out for nitriding, another $ 25 and we are good to go.
I have stuffed a few but for $ 250 ( excluding my time ) I then have a replacement engine that down here I get $ 900 for
#19
7394
Thanks Bert. Although I have never heard of a 'mini-block'.
So I am almost complete swapping in a new short block.
Silly question - where does the ground terminal connect to on the chassis? I must have unhooked it along the way pulling out the engine, and I can't find any diagrams that state where exactly this should be connecting to.
I went to wire up the battery up and pulled the cable completely out.... :laughing:
Have spark, gas at the new carb, flywheel key is not sheared or shifted. If I try to use starting fluid, or crank for 5 or more seconds, I will get a backfire.
