John Deere X300 no compression

[super99]

I was given this mower and they said the motor gave out. It is a Kawasaki 18 horse V twin, it has fire and turns over too easy, no compression on either cylinder. I guess the next step is to take the valve covers off and see if anything moves when cranked over. Are there any know issues with this engine?
Trying to decide which way to go. Thanks, Chris

 

[super99]

Pictures

 

[T.R.K.]

It sounds like you are on the right track. Those engines are about as trouble free as any.
My guess is they overheated it, and kicked a valve seat. Or bent a push rod. Then the kept running it until the other cylinder failed for about the same reason. Check for mouse nest under the fan cover.

 

[super99]

I took the valve covers off today, 3 of the 4 rocker arms were loose. That tells me it needs to be torn down because with the valves not working it should have lots of compression and both cylinders have zero. I did tap the valves on one side and they were all of the way out, not stuck open.

 

[Powered By IH]

I took the valve covers off today, 3 of the 4 rocker arms were loose. That tells me it needs to be torn down because with the valves not working it should have lots of compression and both cylinders have zero. I did tap the valves on one side and they were all of the way out, not stuck open.View attachment 145296View attachment 145297View attachment 145298

Make sure your spark plugs are in all the way...
I would also crank the engine with pushrods and rockers back assembled just to see how much blowby it has out the oil fill tube for curiosity's sake. (piston rings vs valve leakage)
And then take a bottle of soapy water and spray it around the head gaskets to see if they are leaking, again, just for curiosity's sake.
It's not necessary but could be good information later down the road, especially if you could hear where compression is leaking (if there is any).
Make sure to also look for signs of low oil, overheating, and/or especially cylinder glazing or dropped valve seats.
And please keep posting pictures!

 

[T.R.K.]

I'm guessing you popped the pushrods out of the rockers during testing.
You did verify that the pistons are still firmly attached to the crankshaft via the connecting rods, didn't you?
I'm pretty sure that valve clearance should be .004 for intake and exhaust.

 

[Roger in Iowa]

You will not have compression if all the right valves are not working. Air has to get in for compression.

 

[super99]

I'm guessing you popped the pushrods out of the rockers during testing.
You did verify that the pistons are still firmly attached to the crankshaft via the connecting rods, didn't you?
I'm pretty sure that valve clearance should be .004 for intake and exhaust.

Haven't gotten that far into it yet. I just took the valve covers off and the rocker arms were so loose the push rods had fallen out.

 

[Roger in Iowa]

Push rods fell out of place because the valves stuck in pushed in position.
Maybe from lack of proper oil or overheating.

 

[Roger in Iowa]

Looking down thru the flywheel screen do I see grass debris on top of the engine? Could be cause of overheating.

 

[super99]

Looking down thru the flywheel screen do I see grass debris on top of the engine? Could be cause of overheating.

Corn leaves, it sat outside with the hood off for a year or so

 

[super99]

Push rods fell out of place because the valves stuck in pushed in position.
Maybe from lack of proper oil or overheating.

I tapped the valves with a hammer and they all moved

 

[Roger in Iowa]

Put the rockers on and check compression.
Don't need to put covers on. Leave all spark plugs out.

 

[super99]

Put the rockers on and check compression.
Don't need to put covers on. Leave all spark plugs out.

That's the plan but it's gonna be too cold for a few days!!

 

[super99]

Tried to post 2 times with my phone with pictures but it wouldn't allow pictures so I'll try to post them later and see if it works. It got up to a balmy 29° this afternoon so I worked on it some. Both intake push rods were bent. I straightened 1 and put that side back together and set the valves to .006. Try to do the other side tomorrow.

 

[super99]

Trying pictures , guess it worked, not sure why

 

[super99]

Dug deeper today, not so good. It seems that the tappets on #2 cylinder aren't moving. The intake push rod extends out at least an inch farther than it should and doesn't move when turning the crankshaft. Guess I'll be tearing it apart to see what is going on, probably wait until summer when it's warmer and I have more time to spend on it. Thanks for the help so far. Chris