Carb Overhaul, Pointless?

[mr_andyj]

Onan has been sitting for years unloved.

Is it pointless to try to clean the carb? I got it to start and run for a few seconds. Now the carb is flooding and pouring gas out the intake. Great spark, but no bang now.
And whats that hissing sound?

Carbs are cheap on ebay, but I have to wait.

I removed and cleaned the carb. It looks fine, great for having sat so long, but did have some varnish.

Here is pics that include model #. 2004 year

[mr_andyj]

Thanks all.

I installed a cheap china cheapo carb, but plan to clean the old one properly and keep it on hand.

After a few mins the motor smoothed out and the smoking stopped. 120v at the head, though I have not put a load on it since the wires were cut off.

Is it normal that so much heat is coming off the cyl head? The fan moves a huge amount of air over the head, but it is almost too hot to hold my hand there.

I put 15W40 oil in just to run it a few mins as I plan to drain the first oil out really soon anyway and put in 30. I have all this 15w from when I owned a diesel that I no longer have use for, so figured sacrifice that instead of 30w.

I am just keeping this on hand as an emergency home gen as I use a little 2200 gen for camper. What do people do with these, mount them on something? This is not meant to sit on the ground, but hang.
And, wow, is it loud without the cover. The exhaust is quiet but the valves, and even the air flow is loud.

[Orcadrvr]

I have had very poor luck trying to rebuild carbs.
On my pressure washer, I went out and bought a new one from ebay for about $25
and it works great.

[BurbMan]

Also make sure you have clean fuel coming in, flush the fuel lines and replace the fuel filter when you service or replace the carb.

[Lynnmor]

Do your best to revive the old carburetor, those cheap replacements are made in China and have a real bad reputation. Do not use a tip cleaner in the jets and other holes, they can change the flow rate. Use carburetor spray cleaner with a straw to blast thru the passages and don't forget your goggles. A bristle from a paint brush is one way to probe the holes.

[dougrainer]

wopachop wrote:

mr_andyj wrote:
I removed n cleaned the carb with some brake cleaner,

You didnt remove the float bowl because there are no screws huh? Should be able to drill a hole and use an EZ out to remove the screws if you want.

I would guess it to be a dirty needle valve instead of a float bowl that cracked and is soaked with gas.

The float bowl is easily removed. Just one "bolt" on the bottom. Doug

[garyemunson]

I've found acetone is the best cleaner for carb parts that ARE NOT plastic.

[JoeH]

For $40, I'd buy the replacement and then clean up the old one at your leisure and keep it as a spare.

[wopachop]

mr_andyj wrote:
I removed n cleaned the carb with some brake cleaner,

You didnt remove the float bowl because there are no screws huh? Should be able to drill a hole and use an EZ out to remove the screws if you want.

I would guess it to be a dirty needle valve instead of a float bowl that cracked and is soaked with gas.

[midnightsadie]

I,d clean it but buy the proper cleaner, I got plenty time on my hands ,broken ankle .besides that I like to fix things. never liked being a parts changer.

[time2roll]

Save yourself the headache and just replace the carburetor.
Proper cleaning requires removal anyway, install the new and you are done.

[gbopp]

For $36.95 I would replace the carburetor.
I think dedmiston is correct, you could rebuild the old carb and it still may not work properly.

[dougrainer]

Thank California for the problem with Onan Carbs. What Onan says is they do NOT have rebuild kits for the Carbs(1994/5 and newer) because California required that the carbs be sealed for Emission requirements. To the OP, you HAVE to remove the 16 hole NEEDLE jet to correctly clean a Onan carb. Rarely will you destroy any gaskets or seals just removing the BOTTOM fuel bowl. The needle jet is unscrewed from the bottom where the bowl mount bolt secures the fuel bowl. Carb Cleaner will NOT dislodge the gunk from those microscopic 16 holes. You have to use spray Carb cleaner and compressed air to clean out the Needle Jets. Just one clogged hole will cause running problems. Doug

[dedmiston]

If it were me, I'd go ahead and order the new carb. Maybe they can upgrade the shipping to speed it up for you.

Otherwise you could mess with it for days and then still end up having to order the new carb.

According to Onan, their carbs aren't serviceable. That doesn't mean it can't be done, but Onan doubts we can do it and succeed.

[mr_andyj]

I removed n cleaned the carb with some brake cleaner, I didnt have carb clnr. I did not let it soak for days which it might need.
The filer is flowing, I can blow thorough it easy. I figure the fuel pump is working since so much fuel is out.

So, maybe the float is filled with gas and too heavy?

Is it worth trying to fix, or for $36.95 just get a new carb? includes all the gaskets
1 x Carburetor.
3 x Gaskets.
1 x Fuel Filter.
1 x Shut-Off Valve.
2 x Clamps
1 x Air Filter (not sure if this really is)
1 x Tip Cleaner Use For Cleaner Drill
1 x Screw
1 x Seal Ring