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Schrec050584

1989 520h carb

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Does anyone know the kit to rebuild my carb or could i get a new one? My tractor surges and i think the carb needs fixed or rebuilt. Any info is appreciated. 

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Needs to be cleaned, try some seafoam first... might not help but can't hurt. Search on keyword surging and you will find all kinds of answers to your problem. Onan parts.com would have kits.

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48 minutes ago, WHX21 said:

Needs to be cleaned, try some seafoam first... might not help but can't hurt. Search on keyword surging and you will find all kinds of answers to your problem. Onan parts.com would have kits.

 

Onan parts has the kits, but they are pricey and probably not needed.  You can pop the carb top off without removing it from the engine.  Then you can do a decent job of cleaning.  I usually run a soft copper wire through each passage follow up with a carb cleaner spray through a straw.  If that doesn't work, you can remove the carb for a thorough cleaning.  That involves removing the muffler (and exhaust manifold) and also the intake manifold.  Once the intake is off you can remove the carburetor.  Now take the carb apart and soak the metal parts in a gallon can of carb cleaner for about 2 days.  Then follow up with a copper wire and carb cleaner through a straw.  Hope you don't need to go this far.

 

BTW,  NAPA has the gallon cans of carb cleaner.

Edited by Kurt-NEPA
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2 hours ago, Schrec050584 said:

Does anyone know the kit to rebuild my carb or could i get a new one? My tractor surges and i think the carb needs fixed or rebuilt. Any info is appreciated. 

Kurt's suggestions are spot on. The main problem is if the top cover float bowl gasket gets torn up during removal. After nearly 30 years that's a good possibility. If it comes off intact you might luck out! If not the basic carb repair kit is under $50 and we keep those in stock. Part number is 146-0657. New carbs are also available but rarely required. Part number is 146-0496

 

If a thorough carb cleaning does not cure the surging, a leaking intake manifold would be the next thing to investigate.

 

This is what comes in the basic kit.

 

 

1460657.jpg

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I got oil here. What is the tub that goes from engine to air cleaner? Is it a breather? Cleaned carb still surges some but i tightened a intake bolt towards the front of the motor.

20181013_090556.jpg

20181013_090548.jpg

20181013_090545.jpg

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That tube is a breather intake for the crankcase.

 

Sounds like you improved the surging.  Good news, you are on the right track.  Try it again.  Took me 3 times to get mine running right.

 

While you are in this far, check for intake leaks.  I like to play an unlit propane torch around the area with the engine running.  If you get a change in rpm, you have a leak you will have to take care of.  Some people use a can of carb cleaner instead of the torch.

 

 

Edited by Kurt-NEPA
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Is that oil a something that is suppose to happen because it makes it way into air filter some. Also checked compression and front is 90psi and rear is 110psi.

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I guess that there was a significant amount of oil inside the air filter.  If the rubber parts are in good condition, that oil might be caused by too much blow-by, in other words rings or cylinder walls are compromised.

 

While 90 PSI isn't terrible, I would still pull that head and have a look.  It is probably way overdue for a decarbon anyway.  I have had higher compression and found a loose valve seat, and 75 PSI caused by minor valve wear.  A compression test is always good, but it can't tell you everything.

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At the base of that hose is a chamber with a reed valve in it.  I would check to make sure that is in good shape.  Reed valve is number 21, Chamber cover is number 25.  Above the chamber is mesh filter number 12.  I would remove that filter and make sure it is clean.Breather.jpg.6381b19233f40c0a47aad65d547e611b.jpg

 

909337111_OnanP220Breather.jpg.3e8ec0ba44b8a150003fda68d5cd84b2.jpg

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On 10/11/2018 at 12:41 PM, onanparts.com said:

Kurt's suggestions are spot on. The main problem is if the top cover float bowl gasket gets torn up during removal. After nearly 30 years that's a good possibility. If it comes off intact you might luck out! If not the basic carb repair kit is under $50 and we keep those in stock. Part number is 146-0657. New carbs are also available but rarely required. Part number is 146-0496

 

If a thorough carb cleaning does not cure the surging, a leaking intake manifold would be the next thing to investigate.

 

This is what comes in the basic kit.

 

 

1460657.jpg

Do you have a part number for the intake manifold gaskets?

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Thanks Kurt @Kurt-NEPA never realized ther was a reed valve in there. That might be part of the problem I am having with one.

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On 10/14/2018 at 6:18 PM, Schrec050584 said:

Do you have a part number for the intake manifold gaskets?

154-2495 Supersedes/Replaces 154-1446, 154-2745 & 154-1744

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