JD 318 rebuild engine?

[Diamondpilot]

I agree with repowering it. I would love to do the work for you. Where do you live?

If i can't do it any reputable lawn mower shop could handle this in a few hours with one of these kits or better yet you could do it over the course of a few evening's.

Chris

 

[Amvcane]

I have a 1987 John Deer Mower 318. It uses a lot of oil, and smokes. Has gotten worse this past season. I have been told that it cannot be repaired, cannot put in new rings, because the Onan motor at 1400 hours just stops working; and I might as well junk it; that it is all one sealed unit. Any thoughts on this? Thanks.

My new to me 1983 JD 318 with the early b43g Onan was burning oil at a rate of 8 oz per 2hrs of mowing. The engine ran great and had plenty of power, compression was 100psi both cylinders. My friend owns a repair shop and said just keep adding oil for the rest of the season and do a ring job off season, sometimes the oil ring wipers just get tired. I pulled the engine, all wear surfaces looked ok, honed the cylinders and installed new standard rings. The new oil ring was a different three piece design.
The engine runs fine, only consumed 8oz of oil all summer. Probably valve guides. New rings were $21 per side plus an oil pan gasket.
I wouldn't give up on the Onan yet, open it up and see what it looks like, if it is bad, re power the tractor. Either way its not that difficult a job.
Good luck

 

[Sissybitus]

Thank you for this information. As I indicated in my query, I had been told nothing could be done, that the Onan was a sealed unit and could not be worked on! I am so glad for your response, this gives me hope that maybe I won't have to spend a lot of money and can keep my good ole JD!

 

[Amvcane]

Here's a pic of the engine on the bench opened up its not sealed.


New parts are getting hard to find and more expensive. Onanparts.com seems to be the only place. I went in with low expectations and even used the old head gaskets without problem. The small engine warehouse units look very nice and accommodating as a last resort.

 

[Amvcane]

Try again,



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[Amvcane]

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[Blaneypark]

When I blew the side out of my JD 318 engine I started to look around. Found Small Engine wharehouse. Called them told them the serial number of my 318 and in a week had a 20 hp engine in my tractor up and running. Every wireing harness snapped togather perfect. Have bought other engines from them with same results. Great to work with.

 

[Amvcane]

great hearing this, I know this Onan will not last forever, even after the ring job. I was looking at small engine warehouse for a replacement if things didn't work for me, now I know I have a supplier to go to with confidence.