John Deere 420 Garden tractor question

[barretreasures]

Hi been getting a lot of good info from the site Now I Need Help !!!

My Onan P220 in my 1989 420 garden tractor broke a rod this week I think the block is ruined. the cyl. walls look good and are very smooth with very little ridge at the top. My concern is at the bottom of the cyl. wall where it looks like the rod broke off about 3/8" of the wall I know that it is well below the rings and not in the compression area. I also know that I need a crankshaft. Question 1. In the opinion of the experts am I right to assume the block is trash? Was looking at used crank and pistons with new rings. This leads me to Question 2. Will the P224 fit a 420 using the 220 oil base and some exhaust mods? looking at one on ebay. Locally there is a Onan 20.5 horsepower ohv performer. It's out of a Miller trailblazer welder. Trying to do some research on these 2 engines (Crankshaft dia,length, exhaust placement etc ) to determine if either are usable. Any and all help will be GREATLY appreciated. THANKS

 

[RandyT]

Welder engines normally have a tapered crankshaft. May want to look into a bore and sleeve job to see if that is possible.

 

[barretreasures]

thanks

 

[Amvcane]

I believe the onan used in a welding application will have a different amount of fly balls in the governor, you probably won't get the rpm range you need to use in a tractor.
I would go over to Weekend Freedom Machines forum and contact a member named Boomer. He will definitely answer all your questions and supply you with the new or used parts required to solve your problem.

 

[barretreasures]

Thanks

 

[Richard001]

Hi been getting a lot of good info from the site Now I Need Help !!!

My Onan P220 in my 1989 420 garden tractor broke a rod this week I think the block is ruined. the cyl. walls look good and are very smooth with very little ridge at the top. My concern is at the bottom of the cyl. wall where it looks like the rod broke off about 3/8" of the wall

The block does not look ruined to me. That little punched out part is not a real problem.

I know that it is well below the rings and not in the compression area.

I also know that I need a crankshaft.

OK I give up, how do you know that you need a NEW crank?

The photo is a little blurry when zooming in on the journal. You didn't use a cell phone to take this picture did you?

Question 1. In the opinion of the experts am I right to assume the block is trash? Was looking at used crank and pistons with new rings. This leads me to Question 2. Will the P224 fit a 420 using the 220 oil base and some exhaust mods? looking at one on ebay. Locally there is a Onan 20.5 horsepower ohv performer. It's out of a Miller trailblazer welder. Trying to do some research on these 2 engines (Crankshaft dia,length, exhaust placement etc ) to determine if either are usable. Any and all help will be GREATLY appreciated. THANKS

Richard

 

[barretreasures]

Thanks for your input Richard. I did use a cell phone for the pictures. Its probably more the light than the cell phone as I did not turn on the flash. The crank looks pretty scored to me but I'm no expert. I will take some more photos in a few minutes with my camera and try to get some better ones. as for the block I was hoping that was the case. (You know hope for the best expect the worse). I had about decided to just replace the pistons and rods with some used ones with new rings to try and get another year or 2 out of it, then put a repower in it that I can't really afford at this point. Again Thanks

 

[barretreasures]

Some pictures I took at the same time that I didn't post. Let me know if you need more or different

 

[ovrszd]

My Son converted his to a Honda engine for around $2K. I can get specific amount if you need it. Improved the performance of the tractor dramatically. Mows much faster.

 

[Spanner]

I agree with Richard001. The block should be ok.
The crankshaft will probably 'polish' up ok on the journals. Take it (crankshaft) to an engine reconditioning shop and ask them to try to polish it. The scoring is mostly soft metal from the Big End bearings onto the steel of the crank.
If you can get used pistons and rods etc. and it gets you running within your budget, go for it.
Good luck.