520H with 1750 hours

[Keith 21]

I've come across a 520H with 1750 hours on the Onan motor.  Assuming it starts and runs okay, is it possible to know whether the motor has been overhauled?  The asking price seems good to me, but a pricey rebuild could be a few months away if those are original hours.

 

Also it creeps forward when it neutral.

 

[953 nut 55,744]

The hours on the meter could be actual or it could be the key was left on a few times. The only way to know what has been done to the engine is to view the receipts and talk to the people who rebuilt it! If it runs well and has been properly maintained you will probably be OK.

The creeping transmission is a simple adjustment, no big deal.

[Pollack Pete 2,273]

Like 953 Nut said,it depends on how the tractor had been maintained in its lifetime.I've seen low hour machines that were rode hard and put away wet,weren't maintained at all,no oil changes,etc,and the machine is basically junk.Have seen high hour machines that were properly maintained and probably are the better choice to buy.Look it over and talk to the owner.You should be able to tell how the machine was taken care of.Good luck.

[lynnmor 7,352]

Was the oil clear on the dipstick?  Is the air filter reasonably clean?  These are just two things to get an idea of abuse.

[ericj 1,578]

I have a 93 520-H that I bought last year with just over 2000 hours. runs great so I'm not sure if original or not or if the key was left on but it runs real good. I bought it from the widow of the original owner. tractor was fairly clean doesn't smoke or knock, so it depends on how well it was maintained. good luck

 

 

 

 

eric j

[Keith 21]

With these motors are the valves  a common failure?   I know to not run the motor if it knocks but I think these Onans are okay when the valves are in good shape.  Is that generally a correct assumption?

[MalMac 1,331]

These motors are notoriously famous for loosing a rear valve seat. The main contributing factor is the engine gets over heated. Some people go with the thought it gets over heated because the drive belt guard blocks air flow over the back cylinder. This could account for some of the problems, but most come from operator error. Most everyday run of the mill home user did or does not pay attention to the grass screen getting blocked off by grass clippings. This motor has a huge air draw from the flywheel. It gets clogged real easy and real quick. So blocking off the air flow cause this engine to get good and hot. Combined with the belt guard blocking the already restricted air flow that’s why you see a high number of rear valve seat failures. Also most everyday home owners do not give the engine proper cool down time. The difference in materials of the valve seat vs the block. Each cool down at a different rate. Just some cool down time can make all the difference in the world. 

So it comes down to how well that tractor was cared for. If it was not cared for, it most definitely would not have made it to the hours on the meter. So it’s a buyer be ware situation. Go into it with some knowledge of that motor. Myself if you have no way of telling if that motor was cared for or recently been rebuilt, with that kind of hours on a Onan I would be very skeptical unless the price was one you can’t walk away from regardless of the unknown.

[Keith 21]

On 5/2/2018 at 6:17 AM, MalMac said:

These motors are notoriously famous for loosing a rear valve seat. The main contributing factor is the engine gets over heated. Some people go with the thought it gets over heated because the drive belt guard blocks air flow over the back cylinder. This could account for some of the problems, but most come from operator error. Most everyday run of the mill home user did or does not pay attention to the grass screen getting blocked off by grass clippings. This motor has a huge air draw from the flywheel. It gets clogged real easy and real quick. So blocking off the air flow cause this engine to get good and hot. Combined with the belt guard blocking the already restricted air flow that’s why you see a high number of rear valve seat failures. Also most everyday home owners do not give the engine proper cool down time. The difference in materials of the valve seat vs the block. Each cool down at a different rate. Just some cool down time can make all the difference in the world. 

So it comes down to how well that tractor was cared for. If it was not cared for, it most definitely would not have made it to the hours on the meter. So it’s a buyer be ware situation. Go into it with some knowledge of that motor. Myself if you have no way of telling if that motor was cared for or recently been rebuilt, with that kind of hours on a Onan I would be very skeptical unless the price was one you can’t walk away from regardless of the unknown.

I have only seen a video of the 520H running for a few seconds.   The paint and seat looks good from the photos.  Maybe it was care for.   There are not many Wheelhorse where I live.

[Pollack Pete 2,273]

6 hours ago, Keith said:

    There are not many Wheelhorse where I live.

If that's the case,ya better grab it.If you don't.......someone else will. 

[MalMac 1,331]

What Pollack Pete said is true. If you are having a hard time finding Wheel Horses then that will also play a part in your decision. Because driving a good distance to find one can get expensive, especially if unplanned problems shoe up on the trip. 

[Keith 21]

Is it easy to access the spark plugs to do a compression test on the Onan?   There can't be a loose exhaust valve when the compression is normal.   I have a compression tester.  Are the spark plug threads the same as an automobile ?

[MalMac 1,331]

The back cylinder can be tough to get into but it can be done. Yes, a compression test can tell you if a valve seat is loose. Sometimes though, a valve seat will stay implace and hold compression, then when it’s running it will loosen up. Then there are the times that the seat has beat the block so bad that you will find little compression. You are on the right track of taking compression test.