Community Forums

duinit · 08-29-2017, 06:22 PM

Help!! I just bought a 99 Coachman with a Onan Microlite 4000 with only 29 hours on it. The generator will start but will only run for a couple seconds before shutting down. When I spray gas into the carb, it will stay running. What is going on?

hivoltage98 · 08-29-2017, 06:40 PM

Check the carb, it probably needs to be cleaned. A good carb cleaning would help. If your not comfortable doing that Disconnect the hose from the generator and get a gallon of gas with seafoam mixed in. Try running the genset and getting the seafoam mixture in.

BurienTimmer · 08-29-2017, 09:48 PM

It's REALLY important that this generator get exercised monthly year around. There are some excellent YouTube videos on solving your issue.

We have a '94 Tioga with only 9 hours on the same generator that has similar symptoms and I'll be addressing those over the next few days including replacing all of the rubber gas supply hoses.

Also, make sure you have a full tank of fuel as the generator will not run with approximately 1/4 tank of fuel.

OLYLEN · 08-30-2017, 09:21 AM

Fuel, flow, that age maybe hose to tank. Fuel filter, fuel pump, carb you seem to have settled on fuel.

LEN

dix39 · 08-30-2017, 10:36 AM

The same gen with 40 hours in our '94 Flair when we bought it had a similar problem. After checking many of the items already noted here, I removed the rubber fuel line upstream from the filter and gently applied vacuum with my mouth. From doing that I could tell there was a leak in the line. After examining all the line I discovered the leak in a rubber line back near the fuel tank and replaced that part of the line. It was a PITA to get to, but the gen gets fuel now. A vacuum device could also be used, and I have one, but I guess I was on a roll and didn't think of it.

After having a propane powered gen in our last TC for 23 years with no problems, and our first gasoline powered gen in the MH we've had for 2 years with multiple problems, I think I would prefer propane.

Best of luck with it.

Steve

bertible · 08-30-2017, 01:23 PM

The Seafoam-from-a-gas-can method is written up at this website http://seafoamsales.com/wp-content/u...ose-Method.pdf or you can search Seafoam Onan Generator in YouTube to see the movie.

Yesterday I bought the Seafoam and will be doing this for my just purchased Libero. The 12 hour jenny at first started and stopped, then after exercising it every few days for a while with Chevron 91 Techroline in tank, it now stays running but hunts and will not bear the full load of the a/c compressor.

Gary
Delta BC
08 LTV Libero

THenne1713 · 09-01-2017, 01:02 AM

Old age affects rubber, whether tires, window seals, fuel line or radiator hoses.

TIP: My 4000 Emerald, (new to me) at 18y/o, did a little surging and was able to clear by rocking the altitude adjust back/ forth about 12x... guessing it cleared a little varnish? Surge gone.

youracman · 09-01-2017, 02:05 PM

[QUOTE=

TIP: My 4000 Emerald, (new to me) at 18y/o, did a little surging and was able to clear by rocking the altitude adjust back/ forth about 12x... guessing it cleared a little varnish? Surge gone.[/QUOTE]

^^^Thanks for the tip, appreciate it ................ ed s ^^^

THenne1713 · 09-01-2017, 08:16 PM

29 hours is low, but suspect VARNISH CLOGGING due to age/ fuel uncirculated in pump/ filter/ carb, so pull fuel filter ($5-10?) and see if clogged, extend fuel line to a container on ground and verify electric pump ($40+/-) is pumping fuel when cranking (keep open fuel away from sparks); if not, verify VOLTAGE to pump when cranking? Worst case is carb, and if unable to clean/ rebuild, (Float stuck shut or jets varnish clogged) I see them in the $300-$400 range in internet

okcnewbie · 09-01-2017, 08:29 PM

If the sea foam doesn't work you probably should just really buy a new carb. ...I'm pretty sure your model carb is not meant to be cleaned/rebuilt.

duinit · 09-02-2017, 06:53 AM

Update... I checked fuel pump, works fine. I pulled the gas line and ran another line out of a gas can with seafoam in it and after a couple days of doing this and emptying the bowl of old gas and filling it with the conditioned gas, I finally got it running. It is still running at about 90% so I have to do it again. Thanks all for your input. I am told the key is to run it every month, especially since around here we have to deal with gas with ethanol in it. Premium priced gas is not an option.

bertible · 09-07-2017, 10:47 PM

Hi Duinit,
I'm at almost exactly the same place as you with my (now) 14 hour nine year old 4000 micro lite. I've done seafoam from a can twice, the second time leaving it in the carb overnite. Now running even with a/c compressor load, but also still hunting so at 90%. Will keep cycling it with seafoam over next couple of weeks as I mixed a whole can but I wonder if I will have to take the carb off to clean it or replace with new.

Regards
Gary
08 LTV Libero
Delta, BC