Onan Carb. #

[Dlevin 3]

I'm looking for a replacement carb for my 520 HC engine. The manual says it is part # 146-0430. It's not available. Can anyone suggest an exact replacement part number and source? Thanks. 

[ebinmaine 69,275]

Is your own carburetor damaged in some way or can it be cleaned out and rebuilt?

[Dlevin 3]

Not damaged at all. Floods the engine at start up This indicates to me a high float setting or leaking needle valve and, or, seat.  I looked for a kit, but couldn't find one on line. At 28 degrees and 40 mph winds, I thought the quickest way is just to replace it

. 

Edited January 9 by Dlevin

[ebinmaine 69,275]

8 minutes ago, Dlevin said:

Not damaged at all. Floods the engine at start up This indicates to me a high float setting or leaking needle valve and, or, seat.  I looked for a kit, but couldn't find one on line. At 28 degrees and 40 mph winds, I thought the quickest way is just to replace it

. 

 

I've only had my hands in an Onan carb once. That was for @JCM. Very easy to rebuild.

Maybe he would know where to get rebuild kits...

 

Edited January 9 by ebinmaine

[Bill D 2,037]

The needle is probably damaged.  That needle is the same as ones used in some Briggs carbs.  On YouTube there a Taryl video where he uses a Briggs needle to fix an Onan carb.  Both carbs are made by Nikki.  Briggs number is 797410.

Edited January 9 by Bill D

[lynnmor 7,445]

Replacing the carb isn’t very easy since you need to pull the exhaust and intake. You will need new gaskets for the exhaust, intake and carb.  Replacing just the needle and float is very easy, just take a photo and remove the linkage, then 4 screws.  If you are very careful no parts or gaskets may be needed. The Onan Service Manual will guide you thru the carb.  To answer your question, there will be a number on the side of your Nikki carb that is something like 6100-xxx.  My guess is once you remove the carb top you will see the debris causing the actual problem.  Get a spray can of carburetor cleaner and have at it.

[JCM 9,776]

2 hours ago, ebinmaine said:

 

I've only had my hands in an Onan carb once. That was for @JCM. Very easy to rebuild.

Maybe he would know where to get rebuild kits...

 

I bought an OEM carb many years ago to have a spare. Never had any re- build kits. I'm sure I have the slip for it in one my binders. Some pictures are all I can do.

[JCM 9,776]

Found the invoice dated 1-28-08. Toro part  # NN10204   $ 225.00 + tax 11.25 = $ 236.25

[lynnmor 7,445]

2 hours ago, JCM said:

I bought an OEM carb many years ago to have a spare. Never had any re- build kits. I'm sure I have the slip for it in one my binders. Some pictures are all I can do.

 

 

 

 

Note that the top carburetor is the newer "emissions" style having an accelerator pump under that dome held on with 3 screws and a hidden idle mixture screw under the smaller welch plug.  The idle mixture screw on the bottom carburetor is clearly visable.  No rebuild kits were ever produced for the "emissions" carburetors to meet the laws and the only fix was to replace the entire thing.  onanparts.com may have the pumps if you want one.  Most people try to replace those carburetors with older models.

 

Any Nikki carburetor from any 20 horsepower P220 Onan will work, carburetors on the 16 and 18 horsepower engines will also work but jetting and bore size may be different.  Just above the idle mixture is a 3/8" welch plug that hides some small passages, removing that plug is the only miserable job on a Nikki and often that area can be blown clean by spraying carb cleaner with a straw in all openings possible with the plug in place.

[RED-Z06 2,353]

6 hours ago, Dlevin said:

Not damaged at all. Floods the engine at start up This indicates to me a high float setting or leaking needle valve and, or, seat.  I looked for a kit, but couldn't find one on line. At 28 degrees and 40 mph winds, I thought the quickest way is just to replace it

. 

Takes about 10 minutes to get the top of the carb off, takes a good 2 hours to get the full exhaust, clutch, and Intake off to access to mounting bolts underneath.  There's 3 screws and 2 bolts that hold the filter base on, then remove the choke cable, and 4 screws hold the top of the carb on, carb lifts off..float/needle are there and lift out.

 

Carb kits are plentiful but ive never torn a gasket on one, if you need a float needle they come in the kits.

[kpinnc 12,910]

Looks like all the parts in the kit are not needed in most cases. 

 

The trouble part of these carbs is the main jet in the bottom. Unless you have the procedure for removing and cleaning it, I would just spray it out very well with carb cleaner. 

 

Maybe someone here has adjusted the jet before and can chime in. Usually a decent cleaning as well as sealing the manifold cures all the ills on an Onan. 

[RED-Z06 2,353]

6 hours ago, kpinnc said:

Looks like all the parts in the kit are not needed in most cases. 

 

The trouble part of these carbs is the main jet in the bottom. Unless you have the procedure for removing and cleaning it, I would just spray it out very well with carb cleaner. 

 

Maybe someone here has adjusted the jet before and can chime in. Usually a decent cleaning as well as sealing the manifold cures all the ills on an Onan. 

The main jet is so massive you'd need to suck a small animal into the bowl before it would clog🤣

[Dlevin 3]

If the main jet is clogged or possibly clogged, I usually use a tip cleaner from my torches to clean them.

 

[Bill D 2,037]

Did you get your issue fixed?  Probably just a bad needle.  I personally stick with OEM carbs whenever possible.

[Brockport Bill 1,763]

did you check " I SAVE TRACTORS"  they have onan rebuild kits but not sure what model carb