Repowering question

[bravenrace]

Hi,
I have a real old Ransomes Twin Trac 2000 mower with an Onan 20 XSL engine. I only use this machine for leaf cleanup in the fall, as it"s integrated grass catcher works very well. The engine recently went bad (no compression in one cylinder). I want to keep using it, but can"t justify putting a lot of money into it. I"m going to pull it apart to see what"s wrong, and if it"s not too bad (ie - stuck valve) I"ll repair it, but otherwise it would be difficult to justify the cost, as the entire engine could use a rebuild. So what I"m looking for is a good source for used engines, whether it be the same engine I have or a different brand that will bolt in place with little modification. This is a flat 2-cylinder, and I don"t think a V-twin will fit. Any ideas? Do small engine junk yards or used engine dealers exist?
Thanks,
Jim

 

[Anonymous-0]

There are lots of decent used vertical shaft engines around in lawn mower salvage yards. Yes, the salvage yards exist. The people that buy box store mowers either run them out of oil, or they try to pull a trailer or push snow with them and blow up the transaxle.

Good used horizontl shaft engines are more difficult to find.

 

[bravenrace]

Thanks. I guess I forgot to say that it's a horizontal shaft engine. It's an Onan Performer 20 XSL. It looks like a Kohler Command 20 hp engine will fit in the same space, but I haven't looked at all the details yet.

 

[CJ3b_jeep]

Check your local craig's list. I see engines on there all the time.

 

[dhermesc]

I agree with Craigs List idea.

Run your own add looking for a running mower with a blown transmission. There are more out there than you might imagine.

 

[Anonymous-0]

Try smallenginewearhouse.com They have some good prices and can tell tell you an exact replacement engine

 

[Anonymous-0]

I have a 1994 Dodge Shadow, 4 cylinder. The body's getting bad but the engine is still running great, hardly uses or loses any oil at nearly 200,000 miles. Wife says it needs to go. And just lately I thought, it would be great if I could put that little 4 cylinder in my old Bolens, that would make things hum!

 

[Anonymous-0]

Well, my opinion may be prejudiced, but I would rebuild the Onan. It will likely cost a lot less than a repower and will surely take less time and labor.

You can probably get away with a hone/rings/valve job. The crank can be welded and turned or find a good used replacement.

I may have some good used parts if you're in need just contact me offlinel;

 

[Dude11]

I for one think you might be putting the cart before the horse on the onan.First I"d see why it"s running on one cyl.A number of things come to mind;bad coil,bad wire or maybe just a plug.Don"t give up on it yet;they are really tough engines.Just a thought.good luck!Dude11

 

[bravenrace]

I've already determined that it has no compression in one cylinder. I am going to tear into it to find out what is wrong, but thought I'd get some advice upfront. It was still running with only one cylinder, so it may be a broken valve retainer or something like that.

 

[Lee B]

High mileage engines remarkably wind up with no valve clearance very often right up to the point that they quit working or one cylinder lays down on you.

I wouldn't overhaul/repower it just for that if this is the case. Just pull the offending valve, grind the stem until proper clearance returns and put it back together.

 

[Lynn Beccue]

It sounds to me like you most likely have a valve seat problem. It seems to be a common problem in Onan engines and it is usually the intake seat.

I bought one used off of Craigslist that had that problem after fixing that it is great.

 

[bravenrace]

Thanks to all for the replies. I've had a delay and haven't yet been able to find the time to dig into it, but I tend to suspect a valve problem also. When you talk about the valve seat, what exactly do you mean? I know what the valve seats are, but what would likely be the problem with it?

 

[cowboy546]

The block is aluminum and the seat isn't. The seat gets loose and leaks between the seat and block thus low or no compression.

A machine shop can get an oversized seat and cut the seat opening in the block and install a new seat. Make sure they peen that seat in there too.