# Onan Carb cross reference



## hankroberts (Jan 25, 2021)

New to the forum, and NOT a mechanic. I have a Woodmizer sawmill with an Onan P224G engine. Specs for the carburetor call for a pt. # 146-0662 replacement part. The only ones I can find are absolutely ridiculous priced. Are other carbs compatible? I'm particularly looking at the following, which are listed for similar Onan engines:
146-0431; 146-0496; 146-0497; 146-0770. These all show for other P series Onans (P218, P220). The original is a Nikki, but if there's another that will work I'll take it. Any help is appreciated.


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## Milton Fox Racing (May 27, 2014)

Welcome to the boards @hankroberts


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## paulr44 (Oct 14, 2008)

You're up against 2 walls: Onan is very proprietary, and Nikki won't even talk to you. For the time you'd have to invest in finding a will-fit replacement, perhaps even having to re-jet or modify it, I suggest you bite the bullet and just buy the OEM one. Save yourself time and headache. Not to mention I've seen aftermarket carbs. perform poorly, or leak. The mill after all wasn't cheap (the 25HP version today is like 10K), and it's of no use if it doesn't run. I ran into a similar problem with an old motorcycle I had that developed carb. leak, aftermarket parts were available but didn't work. I ended up buying OEM parts resulting a successful repair.

I did do some searching, and came up with nothing. If it helps you digest it, the price I'm seeing for your carb. is typical for any of the better-made twin-cylinder engine brands out there. Some go for a fair bit more.


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## Milton Fox Racing (May 27, 2014)

So is this something you have always had or passed along from a family member? Can we see photos of it?


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## hankroberts (Jan 25, 2021)

Milton Fox Racing said:


> So is this something you have always had or passed along from a family member? Can we see photos of it?


I bought the sawmill used, from a local guy, a little over a year ago: the month I turned 70. He told me then that he'd replaced the carb once, and did not like that model: he'd put a kit in this one and didn't get the performance he wanted. This old guy was a Shop teacher in HS for decades, and rebuilds engines (auto and small) as a hobby. He suggested buying a different brand and replacing it, when I bought the machine. 

I put a kit in it, but that didn't help. No vacuum leaks, new fuel pump, adjusted valves. Going to try a different carb kit, but want to get another carb to see if that solves the problem. There are half a dozen models out there that seem to be the same, and are recommended for engines similar to mine, but I don't want to buy one then not be able to use it. 

I don't have any pics, and don't know how to get them from phone to here.


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## paulr44 (Oct 14, 2008)

What does it do, or not do? Onan's were good for carbon buildup robbing them of power back when I did some RV/Tool truck work decades ago.


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## hankroberts (Jan 25, 2021)

paulr44 said:


> What does it do, or not do? Onan's were good for carbon buildup robbing them of power back when I did some RV/Tool truck work decades ago.


This is on a sawmill. The first problem was gas getting into the oil, and common backfiring. Talking to Woodmizer, three issues: fuel pump; valve adjustment; carburetor. fuel pump OK, adjusted valves, cleaned and put a kit in the carb (help from a qualified mechanic). fuel/oil problem gone but backfiring is worse, and now it takes several minutes on startup before I can open the choke. Used to run a minute or two before leveling out; now it takes up to ten minutes before I can open the choke and run it, and still backfires frequently while running.


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## Milton Fox Racing (May 27, 2014)

paulr44 has the carb answers and has never been wrong in his advice that I am aware of. Not following it is usually when then things go wrong - as the previous owner had already found out.

As for the pictures. When you have the time - and a smart phone - you can use your built in camera phone to take them. Then open up a hobbytalk window on your phone browser. Then copy and paste them (your particular phone functions will vary by name and brand) between the two windows. That will probably be the easiest and fastest way to show pictures of your sawmill to use here.


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## hankroberts (Jan 25, 2021)

Update, for what it's worth. I originally asked a question regarding compatibility of different model carbs. The OEM model [146-0662] is very difficult to find, and very expensive. As I continued to search, I found this info on the Onan Parts website: "146-0662 Supersedes/Replaces: 146-0312 146-0398 146-0415 146-0431 146-0480 146-0497 146-0700 146-0661 and 146-0669". So apparently some of the ones I asked about do indeed interchange. I went out to look at the carb on the engine, that the original owner said he had replaced: turns out it is one of those listed: 146-0700. That carb has an accelerator pump, which the original does not. The rebuild kit I originally installed was for the original carb, and did not have a pump rebuild set. Ordered a new set for this carb and will rebuild again. Found a compatible carb for under $70. The original owner said it should work, if I want to try it. If the rebuild doesn't fix the problem I'll try that.


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## paulr44 (Oct 14, 2008)

I suggest you check for an intake leak, after that check the main jet with an otoscope, the bore of the jet orifice should be brass in color like the jet fitting. Of course, I'd check for fuel delivery issue to the carb. as par for the course.

Just out of curiosity any idea how old is it? If it's an antique, bear in mind breaker point ignition systems when faulty can imitate fuel starvation, albeit rare. Used to fool us sometimes back then.

And as for Milton Fox's compliment, thank you. I do err, just good at concealing it.


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## hankroberts (Jan 25, 2021)

paulr44 said:


> I suggest you check for an intake leak, after that check the main jet with an otoscope, the bore of the jet orifice should be brass in color like the jet fitting. Of course, I'd check for fuel delivery issue to the carb. as par for the course.
> 
> Just out of curiosity any idea how old is it? If it's an antique, bear in mind breaker point ignition systems when faulty can imitate fuel starvation, albeit rare. Used to fool us sometimes back then.
> 
> And as for Milton Fox's compliment, thank you. I do err, just good at concealing it.


Checked for leaks, but will check again after the new kit. Fuel pump is good. The machine is a 95 model, and the carb was replaced about ten years ago, I think. Valves adjusted last month. New fuel system, tank to carb. Electronic ignition: no points.


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## Milton Fox Racing (May 27, 2014)

paulr44 said:


> ....And as for Milton Fox's compliment, thank you. I do err, just good at concealing it.


Must have been before my time! Related to that is one of my favorite quotes from Tommy Alverson "I may not always be right, but I am never wrong."


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