“Puff” now won’t run

[Walhonding520 25]

It has 866 but it was not very well maintained for  about a 10 year period. I brought it back to usable life about 4 years ago. 
 

I think I am going to at least get it apart and try getting new rods (as long as everything else seems ok) and try to get as much more log out of it as I can. I’m just ready to make a big purchase for a new tractor and this one has sentimental value.

[tom2p 2,393]

866 hours not much 

 

hydro should be good - as long as oil / filter was changed at least a few times and was not run too long with grass clippings / debris covering the pump (fins)

 

Eaton 11 hydro is one of more durable components installed on Wheel Horse tractors (and that is saying something given the durability of Wheel Horse tractors)

 

hopefully you can find issue and engine can be repaired 

 

new bearings ... rings ... hone cylinders (?) ... (turn crank ?) ... gaskets / seals ... go over valves ... decarbon of course 

 

but be sure to find the issue - could have been a bad cylinder due to bad valve / valve seat ... resulting in low / no compression ...  dead cylinder ... rods just don't snap (if rod is bad)

 

Edited July 21, 2021 by tom2p

[Walhonding520 25]

So I have finally had some time to tear into it and its a broken rod on the rear cylinder.  Weighing several options right now.  I don't want to get rid of it but I also don't have a ton of time to work on it myself.  To have someone else work on it, all previous estimates have been accurate.  The best I could find was $1500.  I have considered the predator engine, but that will be around $1000 once all said and done.  Thats a good chunk of money to put into an older machine (fro me at least) that will continue to need work, which is time I just don't have.  With a broken rod, what is this tractor worth if I wanted to sell it?   

[Handy Don 10,597]

Check here for a replacement Onan in our classifieds.

 

To answer your question, though...

The market for a horse with a broken leg (sorry) is in two directions.

1. Someone who is willing to repair or re-power to get a 500 tractor worker (or puller?)

2. Parting it out (which takes time and storage by you)

 

For comparison, a good clean working 520 with 850 hours and a functional deck would be asking $1,000 or so in my area. Selling for somewhat less, I'd expect.

 

The repair or re-power buyer wants a bargain. $300+ would be my guess.

Parted is much harder to judge. A LOT depends on the condition. You need hobbyists or those doing their own maintenance on a worker. If the stars aligned I'd guess up to $400 over time--more only if very lucky. Key parts of interest? Good tires/rims, gear reduction steering (if so equipped), mower deck if no holes and spindles solid, a rear sleeve hitch (if so equipped), and a clean wiring harness. External motor parts like the muffler (no holes little rust), carb, starter/solenoid, ignition module, and the governor spider might be of interest to someone rebuilding another Onan (internal parts cannot be interchanged).

 

Another way to look at this is the cost of getting a decent replacement mower vs. what you see as the expected life of your existing unit with a repair or replacement motor. It is possible to get, say, a 14 or 16 hp Kohler or another 16, 18, or 20hp Onan (check ads here on the forum) on your existing tractor without a lot of sweat.

[kpinnc 10,731]

If the rear rod is broken, you need to check the rear valve seats. This is unfortunately a common failure on a Onan-equipped Wheel Horse. Most common in 20hp models.

 

The theory is that the rear cylinder gets less airflow due to multiple reasons. The location of the oil filter and typical lack of using an air seal around the filter, and the location of the belt guard and top bracket that supports it. Combine this with likely debris on the cooling fins, and you can start to see why the rear cylinder tends to run hotter. When the rear valve seats get hot enough, they come out and bind everything up.

 

As I said, that is the theory. You'll often times see folks cut out some holes in the belt guard to help with airflow. Mine is cut out with the support bracket removed altogether. Using an oil filter grommet is a must as well.

 

The pic below isn't mine, but is a good example.

 

Mine is below, though I don't recommend doing it this way. I've never had an issue with making contact with the belt, but it can certainly happen. 

Edited September 7, 2021 by kpinnc

[lynnmor 6,777]

4 hours ago, kpinnc said:

If the rear rod is broken, you need to check the rear valve seats. This is unfortunately a common failure on a Onan-equipped Wheel Horse. Most common in 20hp models.

 

For the valve seat to move over and interfere with the piston, the valve would need to break. 

[Walhonding520 25]

The valves are still seated and have no damage.  I have the cylinder head off and the piston move freely.  The valves still move correctly.  Front cylinder has plenty of compression.