Hi folks. Just got back from one of Uncle's mandated trips to lovely Kuwait, and so of course the '01 Dodge Roadtrek has been sitting idle, inexpertly stored by my buddy (for free, mind). The fridge is full of mold, the shower faucets need replacing, etc. The problem I come to y'all for is the generator carburetor.The gen runs. Here's how to get it started in cold weather. Make sure the van is dead set level. Start it. It dies. Wait 25 seconds, start it again. Do this for 15 minutes, and once it runs past 1 minute, start adding loads - fridge, electric heater, laptop, etc. Then it will run for hours - occasionally it will drop when a load kicks on, but will start right back up.Local RV dealer (not Roadtrek) says the carburetor is a sealed 50 state unit from Onan, and they can't even spray carburetor cleaner in it. All they can do is replace it, which after 3 hours of labor to drop & reinstall the generator, comes to nigh on $1K.So what do y'all do? Keep in mind I'm a full timer w/ limited tools - anything I do is pretty much in someone else's parking lot, unless I can go to the Navy base & use one of the Auto Self Care bays.

The carb can't be rebuilt, and you have to drop the gen-set to replace it.Some members have had some success with running Sea Foam through it, It's worth a try, but I wouldn't get my hopes up to high. Here is a post by Handbasket from a few years ago. He's still on the forum so you can PM him if you have questions.On edit, just getting the fuel filter off is a real pita!"Posted: 01/05/04 03:25pm Link | Edit | Print | 13209874 | IPFor those without the time or inclination to read my ramblings, let me just say, "Believe the Onan manual! Run your genset every month! It's a b!t$h to get to on a B van, at least a Roadtrek, and is likely to cost major money if you let the gas sit in the carb." If you haven't looked, it sits in a box under the floor, only accessable thru an access plate about 8" x 15" that is wholly inadequate to work thru. Let my tale of misery be a warning! That's all. (Warning!! The rest is long and boring!)OK, so when I bought my new-to-me '02 Roadtrek back in the early Fall, I screwed up. The gas tank was almost empty, so we couldn't run the genset. "No problem," thinks I (bad case of wanna new van fever), "Onans 2.8's are pretty reliable, and this thing is close enough to new that I'm sure it just needs gas. It'll be OK...."Yeah, right. 8,500 miles on the clock, 1 1/2 years old, 29.5 hours on the genset. I really didn't think about how long it had been sitting idle on the consignment lot, or with the PO, with no exercise. Well, it wouldn't start. Cranked OK, but no fire. So I got under and took of the access plate. Still couldn't start it using the button underneath, until I figured out the choke linkage and diddled it by hand every time I wanted to start it. Then it loped like crazy, with the revs hunting up and down, up and down, cycling about every three seconds. Putting _any_ electrical load on it killed it immediately. I tried a can of fuel system cleaner, with little result.We finally had some warm weather over the weekend, so I tackled it (don't think Onan would honor the warranty for neglect). Adjusted the choke first (this is why this is in the B van forum, instead of the tech issues forum).... dam', that's a poor design!!! You go thru the access plate at the back, and have to hold the 7 mm wrench in your bleedin' fingertips to reach the two nuts! Don't drop the wrench; it'll go out of reach in the tray under the generator! I _had_ 3 7mm wrenches; now I have two.... Why couldn't they make the access plate full width???!!! Second try got it right, and it starts fine, but still lopes...So, yesterday, I tackled the carburetor... again, very poor design as far as service access. Fuel filter has to come off, housing is in the way of the lower hose clamp, etc.... I'm not sure you can pull the carb without dropping the whole thing out of the vehicle. It doesn't look like it. I settled for taking the float bowl off and spraying some carb cleaner in there, and filling the fuel filter with gas treatment. Still lopes, but not as badly; occasionly smooths out entirely for a inute or two. Definitely some varnish in the carb from sitting. But now starts, runs, and even accepts a load sometimes. Making progress. Even ran the heat pump briefly.So today, I dosed the gas tank with two varieties of cleaner (Techron and Sea Foam) and drove around to mix it up. I then ran the genset long enough to get it thru the system. I plan to start and run it every day for while to keep fresh cleaner in the carb, hoping to dissolve the last of the varnish that way. I'd really rather not drop the genset box.... Dunno if it'll work. But I want anyone who read this far to remember to exercise your generator!!!

I found this on another http://toyotamotorhome.org/forums/index.php?showtopic=4444Edited to make link active.To make a link active yourself just use the Link icon at the top of the message box. Blue/green orb with the picture of a link.Thanks

Backbencher, sorry for your Onan problems. This is a very cautionary tale for all of us, particularly given the bad weather all over the country and the subsequent low or no useage of our RVs. Exercise, exercise, exercise. It is a pain for me to get mine out in the cold and run the genset for an hour at least every month. I do and your post reminds me that I MUST do it. I drive up the interstate to a little town with a good hamburger joint, about 25 miles up the road. I run the genset on the heat pump setting and leave it running while I eat my burger. That gives the coach 50 miles and the genset an hour and a half or so, under constant load. I get tired of this little doings, but your post sure made an impression on me and I again I am sorry for your problems.I read Handbasket's comments My Roadtrek posted above and the link Horizon170 posted. Good suggestion for you and all of us.

Well, the generator is actually running now, charging the engine battery - left the headlights on : ( I think Onan has convinced me to never own another Onan. I'll run some carburetor cleaner through the gas tank, and probably get a 2 stroke Harbor Freight for $88.88 and call it good. I've run the A/C in a Texas summer off one of those little Chinese gennys, and if it will fit in the basement, I'll get a couple of small NATO gas cans & carry them down there. Then if the gen won't start, the little 900 watt 2 stroke will.

If your A/C is an 800 BTU you will need at least a1600 watt gen-set to start it. Good rule of thumb is to double your A/C BTU's to determine the size of the generator needed to start it.Onan's are very good generators, and will give good service for many years if maintained properly.

More Onan 2.8KW questions - carburetor | Good Sam Community

Horizon170
Explorer
Jan 15, 2014
I'm not sure if the 2800 has a fuel pump but I installed a toggle switch to cut off the pump on my Onan 6.5K so I could run the carb dry.
mlts22
Explorer
Jan 15, 2014
My Roadtrek wrote:
I wish the manufactures would offer a fuel cut off to the generator. If I lived where I couldn't run my Class B I would put one on and just run the carb dry. My power washer has one and I never had a problem.

x2. One of the reasons I've had so little trouble with my Yamaha generator is that I turn it off at the fuel petcock, so the carb runs itself dry before storing it. It would be nice to have, at least, a manual valve, or a valve that uses a solenoid so one can remove electrical loads from the genset, flip the fuel switch off, and let the generator run all the gas out of the lines before putting the MH into storage.
scarpi
Explorer
Jan 17, 2014
backbencher wrote:

Local RV dealer (not Roadtrek) says the carburetor is a sealed 50 state unit from Onan, and they can't even spray carburetor cleaner in it. All they can do is replace it, which after 3 hours of labor to drop & reinstall the generator, comes to nigh on $1K.

backbencher, I have an Onan 2800 on my 09 Pleasure Way and I had to have the carburetor replaced. A local RV parts/repair shop charged me $432 to replace the carburetor and change the oil. You price of about $1000 is very high to replace the carburetor.
Horizon170
Explorer
Jan 17, 2014
https://www.prvparts.com/ProductDetails.asp?ProductCode=41793$1,000.00 is way too high. Less than 300 bucks shipped and 100 to put it on or install yourself.
Any time I can do the leg work it saves me money.
Handbasket
Explorer
Jan 17, 2014
For those who're wondering... yes, the 2800 Microlite has an electric fuel pump. Taking the service access panel as the front, it's buried in the left rear corner. No access without taking the green top off of the box. If you've got the service manual, you can maybe sort out which lead in the big bundle coming off the voltage regulator powers it. Then it'd be fairly easy to splice in a switch.

If you're in a dry desert place, fine. I personally wouldn't do it in the humid SE. Too much condensation forming in the electrics that needs monthly running to drive off. I've even read one post on usenet about a 2800 that had the rotor & stator corroded so badly that it was locked up. There's also the copper rings of the commutator that may corrode and cause issues.

Yes, the carb on the 2800 is a non-rebuildable. I've never heard of one being replaced without the green box top being off, so it has to be dropped out from under. A shop would probably bill 3 hours to do the job, 5 bolts, 4 or 5 wires, fuel line.

The DIY alternative to replacing it, if it'll start at all, is to cut the fuel line somewhere forward of the Onan and drop it into a gas can with a heavy dose of Techron or Seafoam. Run it long enought to get the mix in the carb, let it sit overnight, run again to freshen the solvents in the carb. Repeat daily. If it doesn't run smoothly after a week of that, it needs a new carb.

Jim, "Never try to outstubborn a cat."
BudJ
Explorer
Jan 17, 2014
No big deal Jim, but carbs have been replaced without dropping the Onan, like mine. The labor might be about the same as dropping the Onan though, probably a little less.

Bud
tatest
Explorer II
Jan 18, 2014
Motorcycles are moving toward fuel injection, small engines like those in gensets and powers have not yet been pushed there by EPA or even CARB regulations. It's not just Onan, nobody satisfying CARB can supply anything other than a tamper-proof replacement carb for a small engine.

Onan could probably move to port FI on thes small engines, get past the problem of fuel gumming up tiny perts and jets, but would the additional cost also cost market postition? Would FI really solve the "unused engine" problem, on just make fuel system maintenance even more expensive.

Reality is, right now, whether it is your genset, chainsaw, mower, ony brand, when you let them set for months unused with todays gasoline fuels, good chance that they are going to gum up. Real problem with onboard gensets, compared to some of these other small gasoline engines, is that most of the service cost will be labor to remove and replace the genset.

One advantage, maybe only advantage, of LPG fueled gensets is that the fuel does not gum up the carb.
Joecool255
Explorer
Jan 18, 2014
I have a 1996 Explore Class B with a Onan Gen. I have put more money into it than I care to say. New carb. 5 different shops in different states and always another problem with it operating properly. If I could find another gen. maker (never an Onan)to fit in the same place I would in a heart beat. Last trip it runs fine until sometime during the night then just quits. have to get up and restart it. Have herd of NOTHING but problems with Onan.
My_Roadtrek
Explorer
Jan 18, 2014
Most people on here, who maintain their Onan's per the owners manual, have no problems. My ran perfect for 8 years until I sold the RV. Being loud is the main complaint.
Is it possible, that at one time, your Onan wasn't maintained properly?
Where have you heard "nothing but problems"? Probably from owners who didn't take care of their gen-sets, then complain about them.
BillJ999
Explorer
Jan 18, 2014
My Roadtrek wrote:
Most people on here, who maintain their Onan's per the owners manual, have no problems. My ran perfect for 8 years until I sold the RV. Being loud is the main complaint.
Is it possible, that at one time, your Onan wasn't maintained properly?
Where have you heard "nothing but problems"? Probably from owners who didn't take care of their gen-sets, then complain about them.

I'm sure you're right in many of the cases. I would add another issue that Onans seem to have: poor repair shops. That isn't the generator's fault, of course. It seems that a good proportion of the repairs aren't done right, which leads to gensets that are serviced over and over and over ... hence their poor reputation.
Mine ran a little rough when I got it. Now, I can clearly see that the more often I run it, the better it goes. It's nice and smooth now. They do seem to be well built.