Generator will not run

[Mr. Proto]

I went over to change the oil in the generator the other day and it would not start. I thought maybe the fuel filter so I changed it with no luck. I am getting fuel the pump is working and I drained the bowl and it refilled. I next looked at the plugs and though they did not look real bad they were a little black, so I changed them, still no luck. The only code I got was a code 37 on the switch. It is a onan 5.5 gen. I did check the what I believe is the fuel shut off sol. and it apprears to work so I think I need to find the fuel injector. But any help with this would be great. We are supposed to go to the FMCA South rally next week. Help!!!""

["007"]

Do not panic you already posted and people are trying to help.

[Fred and Bonnie]

If you have a fuel bowl, you probably are not fuel injected.

How many hours do you have on the gen. and how often do you run the unit?

Not sure of the code, but I would think the start circuit requires both oil and fuel pressure.

If you don't run the unit at least once a month or you haven't used the unit for several months your carburetor is probably clogged.

Fred

[dieselclacker]

Proto, did you check to see if you have spark to the plugs? Remove one of the plug wires and hold it approx 1/4 inch from engine cyl head or other grounded portion of engine while turning over engine with remote starter switch located on engine. You should be able to see spark.

Don't understand what you mean by fuel injector.

Check in your operators manual from Onan to see what failure code 37 is.


Dieselclacker

["007"]

Here is a LINK FOR ONAN GEN's that may help you.

[JerryForwood]

Whats the fuel level in the main gas tank?
If below 1/4, the gen won't run.

[porscheracer]

Onan carburetors are notorious for gumming up if not exercised often. One trick I have used to get them cleared is to manually hold the choke totally closed until the unit fires (and it may false start several times). Then I override the choke until it warms up enoujgh to stumble along on its own. Then, after about 30 minutes of running - under an increasing load, turning on stuff - it 's usually OK. Then I change the oil and filter, since it's probably gas-fouled.

[Mr. Proto]

Thanks for the replies, I went over some stuff yesterday. I did take of the aircleaner housing and did figure out it is carburated. I pulled the shut off sol. and the brass fitting that holds the bowl on. I checked that the float worked and that the needle valve opened and closed, while I was there I sprayed carb and choke cleaner in the area. After putting it all back together still no run. I did check the oil sending unit with an ohm meter and volt meter and I do believe it is working. It has been probably only about 6 weeks since I used the gen I do try to work it out every month but this time it went over. I have changed the plugs and I am sure I have fire. I like the idea of forcing air back the other way maybe to blow out something but I do not know what. I am not overlooking any run fuse or anything am I?

[GatorDog]

My problem was the linkage that moves the choke back and forth when trying to start. The darn thing was made out of plastic and wore itself out.

Had it replaced with an after market METAL clip and out the door.

[JoeH]

My Onan 5.5 wouldn't start a couple of weeks ago when I went to give it it's monthly exercise. Acted like it wasn't getting fuel. I went back last week and took off the line going into the carb and turned it over and it was getting fuel so I hooked the line back up and it ran like a champ for about 30 minutes and then it died. Did some PD and found the fuel pump had failed. Just picked up a new one and will install it this weekend .

[mygrayhound]

Mr Proto

Don't ignore what JerryForwood suggested. My same 5.5 unit did the same thing last summer. I began the work on the genset before I even sat in the drivers seat. After checking the codes (no fuel) and then taking apart the bowl & checking the filters I thought to check the main fuel level...1/4. After adding 10 gallons it fired and made me feel quite "fuelish"! (Sorry). Good luck.

"05 Suncruiser 37B W24

[Mr. Proto]

I went over yesterday and tried something different, I held the choke almost completely closed and ran the gen for about 5 min. I was getting tired of holding the choke valve, as soon as I let for of the butterfly I stalled out so now I am thinking of an air leak, like I am running to lean. I am thinking of replacing the base gasket, maybe that insulator block between the carb and intake. I did not see any other place for a "vacuum" leak. The run yesterday told me that I am getting fuel and spark and after running for 5 or more min. I should be getting enought of both. Any thoughts?

[NeilV]

Quote:

Originally posted by Mr. Proto: I went over yesterday and tried something different, I held the choke almost completely closed and ran the gen for about 5 min. I was getting tired of holding the choke valve, as soon as I let for of the butterfly I stalled out so now I am thinking of an air leak, like I am running to lean. I am thinking of replacing the base gasket, maybe that insulator block between the carb and intake. I did not see any other place for a "vacuum" leak. The run yesterday told me that I am getting fuel and spark and after running for 5 or more min. I should be getting enought of both. Any thoughts?

Sounds more like your carborator jets are plugged and need cleaning. The choke bypasses or augments them via a secondary port when you close it to allow extra fuel to flow for starting the engine.

It is probably time to pull and clean the carb.

[Mr. Proto]

Problem solved, I have taken all of your advise and finally pulled the Carb and cleaned it. I only had carb and choke cleaner but I blew it down the various holes etc. I pulled the upper air bleed with the main pickup tube and sprayed that really well along with all the other various orifices. When I re-started it ran, so I put it all together and ran it for almost an hour with both AC units on to give it a load, I had to set the t-stats down to like 20, I will run it again tomorrow just to see that all is well before I head to the rally on Tuesday. Thanks again.