Cummins Onan 2500 OG LP Question

[valueseer]

Need ideas and suggesions for a 2015 Winnebago ERA 170X with Cummins Onan 2500 generator mounted underneath vehicle aft of rear axle.
Problems starting genny after 9 yrs without problems. Starter motor is powered and rotates but no lightoff/combustion. After new spark plug, change of oil to appropiate level and ensuring vent tube was clear.
When manually moving carburetor valve/diaphragm engine starts and will run continuously with no issues.

Access underneath van in genny box is extremely tight. I cannot change air filter due lack of space and would need to remove entire air filter assembly to fix/replace carburetor. Any suggestions on fixing carburetor issue besides removing entire genny module from underneath vehicle?

 

[Mikeflbmer]

I had a similar issue and it was very hard to get to it and work on it........I ended up removing the onan and getting rid of it and now have a rear mounted pulsar 4300/3500 inverter generator with remote start........quieter, more convenient and removed about 150 lbs of weight going down the road.......

 

[beauregaard]

I had a similar issue and it was very hard to get to it and work on it........I ended up removing the onan and getting rid of it and now have a rear mounted pulsar 4300/3500 inverter generator with remote start........quieter, more convenient and removed about 150 lbs of weight going down the road.......

How and where did you mount it, in the original Onan location?

 

[booster]

I am curious about the saving of 150# as that is about the weight of an Onan and the mounting brackets.

I think most of the 4500/3500 generators are in the 80-100# range, that Pulsar looks to be listed at 92#, and also would need some kind of mounting unless carried inside the van and moved out when needed.

 

[mik mikgil@icloud.com]

Need ideas and suggesions for a 2015 Winnebago ERA 170X with Cummins Onan 2500 generator mounted underneath vehicle aft of rear axle.
Problems starting genny after 9 yrs without problems. Starter motor is powered and rotates but no lightoff/combustion. After new spark plug, change of oil to appropiate level and ensuring vent tube was clear.
When manually moving carburetor valve/diaphragm engine starts and will run continuously with no issues.

Access underneath van in genny box is extremely tight. I cannot change air filter due lack of space and would need to remove entire air filter assembly to fix/replace carburetor. Any suggestions on fixing carburetor issue besides removing entire genny module from underneath vehicle?

Building a larger access door would be benfcial. I found a different route to issues with accessibility to the OnAN. I mounted the fuel filter and fuel pump remotely from the onan housing so that it can be serviced without removing the gen set The fuel pump is a high failure item. Dropping the gen set is easy if you plan ahead. Build a support box to fit around the bottom of the Onan. Then bolt the box to a floor jack so it cant fall out. Takes all the hassle out of lifting and dropping the 125 lb bulky generator. Much easier to service when on the ground or bench. Make it a easy job so you won't avoid servicing it. Mine is mounted inside under the bed, which require dead lifting to get it out. not fun

 

[mdstrum]

We have 2019 Era 70A 4x4 and found that with a motorcycle floor jack and about 20-25 minutes we remove unit, this makes it much easier to work on. You might need a new coil, or it could be the the springs for carborator that need to be replaced....removing the unit and bench testing is how we resolved all our issues (we haved over 1500 hrs on our unit and decide to upgrade to the newer inventer model vs repairing with stater wore out (we going through brushes ever 100 or so hours).

 

[RT-NY]

Make it a easy job so you won't avoid servicing it.

This is very good advice! People seem to be very unwilling to drop the Onan generators in the Roadtreks, but it shouldn't be too difficult to do -- there are only four or five bolts and three connections to deal with. With a few mods (like adding an accessible junction box for the AC line and a fuel shut-off valve), it could be an easy job. I find the Onan very reliable and indispensable for charging the battery when boondocking, but it does require service sometimes.

 

[booster]

When I removed the generator from out 07 C190P Roadtrek it was nowhere near as easy as others are mentioning. The generator itself is easy, I used a flat topped transmission jack, but the wiring did and the fuel line would have been problems.

The fuel line went to the top of the gas tank at the fuel pump flange and wasn't accessible from under the van or through the small access hole in the driver side storage bin. A few years earlier I had cut into the fuel line to add a valve and port so I could put put gas without ethanol into the generator between trips.

The wiring could not be disconnected at the generator and was run in sealtite conduit to the driver side bolster that also has the water hearter, water pump, transfer switch, and a big speaker for the surround sound. The conduit did not go into the cabinet and ended at the van body floor with open 110v wires after that there were not even in sleeving. The conduit fitting was under all the water hoses so barely could see it and the whole thing was gooped up with silicone on both the underbody side and bolster side. Quite a mess to get out. I took the sealtite underbody nut off the pull the conduit out of the fitting but the loose wires were glued into the fitting with silicone and wouldn't come out. If I wasn't removing the generator permanently, I probably would have just cut the conduit and wires and added junction box as others have mentioned. Very user unfriendly and no wonder the cost of removing and servicing an Onan is so high at a dealer or Onan service center.

Ours is 10 years gone and never missed it for an instant. We also never use shore power unless we hit a very hot place and need AC, especially if we pull in late with a very hot van from a long drive in over 100*.

 

[RT-NY]

Fortunately, in my 1999 RT 170, both the fuel hose and the ac line are readily accessible and there is a lot of slack in both. I could actually drop the generator without disconnecting either.

So, I guess it depends on how it is hooked up. And, like everything else, everyone has different needs depending on their setup and how they use the van.

 

[valueseer]

Thanks to you all for the insightful ideas.

Talked to people locally about my problem. Like previous comments, people say dropping the Genny is relatively easy and makes access more available.

Visited the local Cummins service/parts center. Individual parts for my HGJBB(specA) are "obsolete" but larger parts are available. On my LP Onan, there is no carburetor but it is called the "mixing valve assembly". That assembly is $1250!

The Cummins technician, who was familiar with my underneath rv mount, recommended replacing the unit because of the expense of larger individual parts and the failure rate of the starter motor, coil and generator brushes. He stated that the replacement generator (2.5HG2AA) is more reliable, parts are available/less expensive and the replacement generator is same size as the old Genny (HGJB.

I asked him about the difficulty of replacing the generator for someone like me who is a 3 out of 10 mechanical ability. He said it was totally doable for someone like me, but I would have to lengthen both the fuel line and the battery cable because they are switched sides on the new Genset. He said the toughest part of replacement is the AC electrical wiring, as each manufacturer has different attachment points inside protective covering.

Now I will think about the best solution for my situation.

 

[hbn7hj]

I replaced the 2800 Onan with the 2800i last year. No problems, no regrets. The fuel injected version starts instantly. Very quiet. Replacing the 2800 is a much better option than repairing. I removed a working unit. So far it has been a good move.

 

[valueseer]

have a conclusion/epilogue to this thread:

TSB from Cummins # TSB200040 dated 28-Feb-2020 ... The TSB is titled "HGJBB Crank but No Start or Hard Start due to Leaking LP Hoses"

I replaced the high pressure hose and the low pressure hose on the Onan Cummins HGJBB. The Generator now performs normally.
Used the (expensive) Onan Cummins hoses (part # A041E042 and part # A041E044)

Followed the advice and protocol of the following link:
2017 Airstream Interstate Onan Generator won't start

I am not a mechanic but the job is straightforward if you follow the steps listed in the previous link.

If you do the maintenance yourself, I would recommend the following as necessities:

1. 6 inch height wooden ramps.
2. Motorcycle jack from Harbor Freight
3. Creeper trolley

Replacing the actual hoses is a PITA (pain in the ass) ... definitely requires removing the generator from the sprinter and working from bench or lift.

AC electrical hose/wire removal is a very time consuming process .... but my Winnebago ERA electrical removal had to be detached inside the coach.

I personally feel money that I spent was well worth the effort and doing the project by myself gave me self satisfaction.