Yet another Onan running like **** thread. HELP!
Hi all!
Short version first:
1999 Onan MicroLite 4k
Been sitting for years
new fuel pump
new fuel filter
new air filter
oil change
pulled and cleaned carb twice
two bottles of Sea Foam
Runs like **** with no load.
Runs slightly crappy with a load. Engine "Hunts."
Long version:
Got an old 1999 Four Winds class C out of Mom's yard and have been working on it. Lots of work. Lots and lots of work. It's been sitting for at least 5 years seeing little to no action. All the fuel was varnish. Plumbing cracked. Brakes sticking, coils where shot. Same old RV Blues.
My current issue, however, is with the genset. Onan Microlite 4k. I replaced the fuel pump, fuel filter, air filter, and cleaned the **** out of the carb a couple of times and got it back up and running but it runs like ****. It "hunts" without a good load on it but runs reasonably well with the air conditioning on with only a few hiccups every now and then. Course when the AC kicks on it dips down momentarily to like 80V which also sucks.
From what I've read this points to the carb being dirty, or possibly the carb needing adjusting. So I worked on the carb... a lot. I exercised the generator several times for an hour each time. Ran like ****. So I pulled the carb off completely, sprayed and wiped the bejesus out of it. I unstuck the fuel shut off solenoid and tested it with a 12v source. Cleaned the float and needle and made sure they move well. Linkage and butterfly valves all move easily. Did all this and ran a can of Sea Foam through it in a 50/50 mix of it and high octane gas. It still ran like ****. So I pulled just the carb bulb, float and needle and cleaned everything again, did another round of sea foam and gas. Same deal. Visual and from what I can test the carb should be good.
I can't really do a carb adjustment because it's only got a throttle stop screw and a main/altitude adjustment screw on this carb. No idle adjustment screw. Also, I don't have a meter that reads frequency. I have no idea the history on this genset or if it's ever been adjusted by anyone. I do know the main/altitude adjust screw was very loose and only a few turns from popping out when I had the carb removed. And the main adjust screw "limiter cap" is missing. I followed the service manual and set the main adjust by turning it until I felt resistance, then backing it out two full turns.
Is there anything else I can do before I just take it to a Cummins repair shop? I'm about at my end with this thing. Got them Old Onan Blues. Lawd lawd....
Any advice is greatly appreciated.
Short version first:
1999 Onan MicroLite 4k
Been sitting for years
new fuel pump
new fuel filter
new air filter
oil change
pulled and cleaned carb twice
two bottles of Sea Foam
Runs like **** with no load.
Runs slightly crappy with a load. Engine "Hunts."
Long version:
Got an old 1999 Four Winds class C out of Mom's yard and have been working on it. Lots of work. Lots and lots of work. It's been sitting for at least 5 years seeing little to no action. All the fuel was varnish. Plumbing cracked. Brakes sticking, coils where shot. Same old RV Blues.
My current issue, however, is with the genset. Onan Microlite 4k. I replaced the fuel pump, fuel filter, air filter, and cleaned the **** out of the carb a couple of times and got it back up and running but it runs like ****. It "hunts" without a good load on it but runs reasonably well with the air conditioning on with only a few hiccups every now and then. Course when the AC kicks on it dips down momentarily to like 80V which also sucks.
From what I've read this points to the carb being dirty, or possibly the carb needing adjusting. So I worked on the carb... a lot. I exercised the generator several times for an hour each time. Ran like ****. So I pulled the carb off completely, sprayed and wiped the bejesus out of it. I unstuck the fuel shut off solenoid and tested it with a 12v source. Cleaned the float and needle and made sure they move well. Linkage and butterfly valves all move easily. Did all this and ran a can of Sea Foam through it in a 50/50 mix of it and high octane gas. It still ran like ****. So I pulled just the carb bulb, float and needle and cleaned everything again, did another round of sea foam and gas. Same deal. Visual and from what I can test the carb should be good.
I can't really do a carb adjustment because it's only got a throttle stop screw and a main/altitude adjustment screw on this carb. No idle adjustment screw. Also, I don't have a meter that reads frequency. I have no idea the history on this genset or if it's ever been adjusted by anyone. I do know the main/altitude adjust screw was very loose and only a few turns from popping out when I had the carb removed. And the main adjust screw "limiter cap" is missing. I followed the service manual and set the main adjust by turning it until I felt resistance, then backing it out two full turns.
Is there anything else I can do before I just take it to a Cummins repair shop? I'm about at my end with this thing. Got them Old Onan Blues. Lawd lawd....
Any advice is greatly appreciated.
