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100Akers · 08-24-2016, 10:12 PM

It's in a '96 Allegro Bay, and sat for 2 years. Cranks good, starts to fire, but won't run. Since it sat for so long with fuel in it I imagine the carburetor needs to be rebuilt. It's a Nikki 146-0633, and I've had no luck finding a rebuild kit. I can take it all apart, clean everything, and Permatex it back together, but I'd really rather do it right. So my first question is: Does anyone know where I can find a rebuild kit for a 20 year old carburetor?

Assuming that idea strikes out, does anyone have any better ideas of how to service the carb? Spraying carb cleaner didn't help.

And third question is: Does anyone have any other suggestions beside the carb?

MtnTrek · 08-24-2016, 11:42 PM

Fuel pump delivery is ok?

I've read threads where rebuilds get mixed reviews and they tend to eventually bite the bullet & replace the carb in frustration. YMMV

possible carb kit:
Onan 146-0666 Carburetor Kit w/ Gaskets NEW!#

good luck.

LookAtUSNow · 08-25-2016, 05:27 AM

Shpuldnt it be throwing some codes out to indicate an issue. Our diesel Onan had similar problems but it was cooling related, radiator had clogged up and wasn't circulating properly, new radiator solved our problems. My apologies, I thought yours was Onan, I'll leave the post maybe it will provide a different rabbit hole to search.

100Akers · 08-25-2016, 06:44 AM

MtnTrek - That kit has a title of 146-0666, but the description says it's for the 146-0633. What's the difference?

Fuel flow seems OK, I pumped about a pint of gas into a can at a much greater flow rate than the generator should need, but didn't check the pressure.

100Akers · 08-25-2016, 06:46 AM

LookAtUSNow - Where should codes show up? There's no display unit anywhere around that I can see. Mine is an Onan, but gas not diesel, and back in 1996 things tended to be more mechanical and less electronic.

LookAtUSNow · 08-26-2016, 06:23 AM

My RV is an 01, so not to far off, my switch to crank the gen has an led light on it and it flashes to show codes a bit like morse code, you would need the owners manual to decipher the codes. Looking at an online manual for the Onan 7000 indicates (not sure about year model) it does include a fault code. One blink high temp coolant, 2 blinks low oil pressure, 3 blinks is a fault service code, press stop and a second set of fault codes should blink. Looking at the manual, for cranks but won't star, do you have enough fuel in your tank for it to run, fuel supply shutoff valve open, carbon deposits on plugs -replace plugs and low oil level. You can find the manual online for the gen if it applies that far back. I did come across a few post that stated cleaning the carb could fix it, also one iteresting post similar to your, RV sat for a while and battery was not able to provide enough power to get gen running, would turn over but not run. You could always call Onan, have your model and serial number handy. I've always had good luck with those guys.

100Akers · 08-27-2016, 04:52 AM

Thanks LookAtUSNow. Mine doesn't have a light anywhere, so I guess the change happened between 96 and 01. I changed the plugs, gas tank is full and fuel pump delivers it to the carb, and batteries are at full charge. Oil is full, but I didn't try bypassing the low oil switch if there is one, so will try that.

I wrote the seller that MtnTrek referred to to find out if his carb kit will fit, haven't heard back yet. If neither of those do it I"ll try calling Onan.

Afubar · 08-27-2016, 05:49 AM

When I had problems with my Onan starting, I too changed the fuel filter, oil, oil filter, and plugs, didn't help, person in a 5th wheel next to me said he had the same problem and he had to replace the control board, did that, no go. Then I called Flight Systems, the guy in the service department listened over the phone as I held down the start button and he said I probably needed the voltage regulator, Bingo! I replaced it (yes, by myself) and it now purrs.

You might want to contact them. What have you got to lose?

Generator & RV Controls Repair and Replacements, Engine Monitoring, Idle limiting

Kaye

Bcail · 08-27-2016, 06:18 PM

Just reserected a '92 Marquis 7000 that had been sitting for several years. It would sputter but wouldn't run. The problem ended up being the fuel line feeding the fuel pump. It was dry rotted to the point the fuel pump would lose prime in between runs. The easy way to check this is to spray some ether (starting fluid) into the air filter and then crank the generator. If it fires up better with ether, you have a fuel problem. Make sure the suction fuel line into the fuel pump is not dry rotted. If it is, change ALL of the rubber fuel lines.

TQ60 · 08-28-2016, 11:28 AM

Get some chemtool.

Both the spray and pour in.

First with the spray locate the vent for the carb and spray some in there and start the unit.

Spray in carb to run off the cleaner.

Next remove line from tank side of fuel pump and add a small hose from pump to pour on Chem tool.

Run genny on it then let soak then run again.

This stuff will clean out the gunk.

100Akers · 09-01-2016, 11:12 AM

TQ60 - My NAPA store says SeaFoam is the same as ChemTool, and I've been trying it. Generator runs great as long as I keep spraying. Sticking the fuel line into the can it sucks it up just fine, but won't continue to run for more than a few seconds after I quit spraying. Intermittent blasts, doesn't need to be continuous. Been playing with that routine for a couple of days. Seemed like it got better after the first day, but still won't run on it's own. I'll continue to try every day until it's sucked up the whole can, but I'm not optimistic. At least this confirms that it's not the fuel pump, filter, low oil switch, gas level in the tank, gremlins, or any of the other likely suspects. I really need to rebuild that carburetor!

TQ60 · 09-01-2016, 12:05 PM

If it runs fine on the solvent then put some fresh gas in same can and try that.

You may have a crack in fuel line allowing fuel pump to suck air and loose prime so to speak.

100Akers · 09-01-2016, 06:14 PM

It runs fine when the solvent is sprayed into the carburetor, does not run on solvent alone from the can. One of the first things I did was replace the fuel line, including proper worm gear clamps. The solvent in the can is being sucked by the fuel pump, I can see the level going down. I'll try fresh gas instead of solvent tomorrow, but I suspect it's the needle valve or the float that's messed up.

TQ60 · 09-01-2016, 06:32 PM

If will not run from can it is float or valve.some have a screw in the bottom to control fuel flow.

Not familiar with your specific one but many are common.

If you can pull carb off that would be best.