JD 318 with Onan P series engine

[wooden]

2 days ago out in the front yard mowing away when I hear a loud POP!! that i Thought was aa rock in the blade tray, but I was up along a wall and nothing came flying out. This set me to thinking this was strange. Minutes later I pulled up infront of my workshop to blow off the engine as I always do before putting the machine away, when I noticed an excessive amount of engine oil running down the right side of the tractor. Anyone care to take a stab as to what happened?? A blown headgasket maybe??? I have not attempted to pull it apart as yet, to fiind the problem,because My 2720 can carry the load from here , but I love that little 318 and want it running. That being said, I think that engine is way tired, and maybe time to scrap it. What are my re power options?? and possible cost?? Help!!!!! Onan discontinued this motor and I am guessing a re build kit. could be hard to find.

Wooden

 

[Dave M7040]

Sounds like you threw a connecting rod which went through the side of the block.
If you look closely I expect you will find a hole bashed out from the inside.
Engine will be scrap.
This site offers kits to replace your onan engine with a Honda for just under $2,000
John Deere 318 Replacement Engines - Repower Specialists
Dave M7040

 

[jaydee325]

My understanding is the Onan engines are expensive to rebuild. I think a repower is your best bet.

I got a lot of hits searching this site for Onan.

Small engine warehouse has repower kits for most any tractor.

Link

 

[Lilguy]

My last air cooled tractor was a Simplicity with an Onan twin. It lasted 3 seasons and needed a rebuild, cost just shy of a grand in 1984. Switched to Kubota Diesels in 85 and they are still running today.
Onan makes great engine for moderate lawncare and generator use, but heavy utility tractor use needs diesel power. I agree with the Honda upgrade, that's a no brainer.

 

[wooden]

Sounds like you threw a connecting rod which went through the side of the block.
If you look closely I expect you will find a hole bashed out from the inside.
Engine will be scrap.
This site offers kits to replace your onan engine with a Honda for just under $2,000
John Deere 318 Replacement Engines - Repower Specialists
Dave M7040

Sorry but the engine is running like a clock so there is no rod problems. I'll be opening it up partially today
for a closer inspection and I am almost certain it's a head gasket. I have pulled the heads before and re torqued them back to spec, but the gaskets were not replaced because they were in excellent condition at the time. I found a Brigs /Vanguard re power for a 317 that is a plug and play unit. I wrote to the company to request information on the 318 and pricing on their 23 HP or an 18 HP used in the 317's
Will post my findings in a few days

 

[davesl708]

check the oil filter. It may have plugged and failed.

 

[Dave M7040]

Changed my mind once I re read the initial post which was about grass cutting not snow removal