520H Help

[bottjernat1 2,194]

I agree with alot of folks on here. when hauling it you could have jared some crap loose in the carb or else where like the pump or inline filter. I personally would just do a go threw on the fuel system. clean the carb change the fuel filter. It wont take you long and it is the cheapest and easiest thing to start with. You have a great lookin horse. Take pride in what you have she will last you many years. I own all older stuff id love to own a new style like what you have they are very nice machines!! Good luck

[DG1776 20]

On 6/18/2019 at 6:36 PM, roadapples said:

Agree. Look to be different widths...

 

After helping Huey with the tractor today I can confirm the front tires are two different widths.  Totally over looked that when we picked it up.  It's still a clean tractor though. 

Edited June 23, 2019 by DG1776
typo - specification edit

[WVHillbilly520H 10,376]

On 6/18/2019 at 3:38 PM, HueyR9 said:

I bought this 520H 20hp Onan Wheel Horse this last weekend for $1400.  When I picked it up I, along with a friend that knows more about Wheel Horses than I do, test drove it and it started right off and everything worked and ran perfectly.  We then had to drive it about four hours home.  Also, due to my error, we had to remove the deck to get it on the trailer.

 

When I got it home it started fine and came off the trailer without issue.  The next day I tried to reattached the deck and was having issues getting everything aligned correctly.  I also tried to start it and it would not run.  I had to have the choke fully open, it would pop off, and then stutter out.

 

This morning I got the deck attached correctly, I believe.  The left side of the deck hangs a little lower than the right side (as you are sitting on it).  I started it up and it ran for a couple minutes just fine and then stuttered out.  After a trip to the gas station and filling up the tank to ensure there was enough fuel in the mower, I was able to get the engine to run for approximately 5 minutes from half throttle to full throttle with the PTO engaged.  After shutting the PTO off and idling the engine down it stuttered out again. 

 

After several attempts to get it going again it would not even turn over so I walked away for a couple minutes.  I then tried again and it would only run with the choke fully open.  Trying to lower the choke caused the engine to stutter out again.

 

Any help trouble shooting this would be greatly appreciated.  Also, this is my first Wheel Horse and first time posting on this forum so I apologize for anything I may not have added that would be pertinent to know.  

Just so you know the battery hold down is mounted incorrectly....it (angle iron) should be "square" over the front (engine) edge of the battery next to the cable posts.

[WHX?? 51,916]

5 hours ago, DG1776 said:

 

After helping Huey with the tractor today I can confirm the front tires are two different widths.  Totally over looked that when we picked it up.  It's still a clean tractor though. 

Small matter DG ...clean is what all that counts.....let us know if you or Huey needs any help. 

[HueyR9 8]

So DG1776 and I have now replaced the fuel filter, fuel pump (not to factory original), and cleaned the carburetor as well as cleaned the fuel lines.   The 520H still will run fine for a few minutes then it acts like it is not getting fuel and dies.  Seafoam has also been added to the fuel tank.

 

Also, as we are sitting here trying to get things figured out, we noticed when left idling at 3/4 to full throttle, this throttle linkage to the carburetor would move on it's own causing the engine to wind down and die.  As we continued to troubleshoot and brainstorm we noticed that when this happened, fuel would spit up and out of the carburetor and as a result, the engine would die.

 

Edited June 29, 2019 by HueyR9

[WVHillbilly520H 10,376]

2 hours ago, HueyR9 said:

So DG1776 and I have now replaced the fuel filter, fuel pump (not to factory original), and cleaned the carburetor as well as cleaned the fuel lines.   The 520H still will run fine for a few minutes then it acts like it is not getting fuel and dies.  Seafoam has also been added to the fuel tank.

 

Also, as we are sitting here trying to get things figured out, we noticed when left idling at 3/4 to full throttle, this throttle linkage to the carburetor would move on it's own causing the engine to wind down and die.  As we continued to troubleshoot and brainstorm we noticed that when this happened, fuel would spit up and out of the carburetor and as a result, the engine would die.

 

You still have dirt/debris/ethanol crystals something still in the carb, you really need to complete remove it and soak in a can of carb cleaner...https://www.berrymanproducts.com/products/eco-friendly-products/berryman-chem-dip-carburetor-and-parts-cleaner/...or similar, also I advise you actually change out those rubber fuel lines with new ethanol resistant ones...that arm moving is the governor "hunting" and until the carb is completely soaked/cleaned it will continue.

[DG1776 20]

Thanks for the response.  We were hoping we could get away with not fully removing the carb.  Looks like it unbolts from the bottom.  Any pointers or tips from other members who's done this before would be helpful.

[WVHillbilly520H 10,376]

8 minutes ago, DG1776 said:

Thanks for the response.  We were hoping we could get away with not fully removing the carb.  Looks like it unbolts from the bottom.  Any pointers or tips from other members who's done this before would be helpful.

You have to un bolt the entire intake manifold and may need new gaskets, or be extremely patient with removing/replacing the carb bolts, it also may be a good time to pull the heads decarbon the combustion chambers and adjust the valve clearance as well...have you downloaded the Onan repair/service manual from our manuals section, this will help you out alot, also mark the holes the carb/governor linkages are currently in before removing (paint or permanent marker).

[DG1776 20]

Much appreciated!  Thanks for the help.

[lynnmor 7,859]

11 hours ago, WVHillbilly520H said:

You have to un bolt the entire intake manifold and may need new gaskets, or be extremely patient with removing/replacing the carb bolts, it also may be a good time to pull the heads decarbon the combustion chambers and adjust the valve clearance as well...have you downloaded the Onan repair/service manual from our manuals section, this will help you out alot, also mark the holes the carb/governor linkages are currently in before removing (paint or permanent marker).

 

 

Yep, and to add to that, check that the intake is sealed between the two halves.  The intake may have a cut in it from a heat shield, so check for that and cut some clearance in the shield.  Since the exhaust will be in the way, this would be a good time to pull it then glass bead and spray with Rust-o-ileum high temperature paint.

 

When you reassemble, use only genuine Onan intake & head gaskets, cheap import parts will cause problems.

 

I am starting to think that you have a valve seat so loose that the problem comes and goes, pulling the heads for de-carbon is a normal part of maintenance and will allow an inspection of the seats.

 

That breather hose is rotten, replace it to keep dirt out.