Onan 2500, loosing power?

[Mean_Jeanne]

Hello all:

So I just read a thread by "Old Pilot" (thanks for posting) and I'm having similar, but not exactly the same, problems with my Onan 2500, in that it's suddenly not providing enough power to run certain functions.

First off, I have a 2007 Roadtrek 170 P, with an Onan 2500 Generator (gas powered). The Onan was completely rebuilt a few years back, and it's been running perfectly since then...starts up fine, powers the microwave, plug-in appliances (toaster) and the CoolCat AC (I boondock with the 170).

I had an isolator problem in the spring and had to run the generator a lot more to charge the house battery, but it worked like a champ and still powered everything. I since rectified the isolator issue (thanks loads for your help "phantomjock"), and everything was still fine with the generator to power the aforementioned functions.

However, the last trip I took, I started the generator (all good) and it powered the microwave fine...although it did "sound" a little bit rougher?! Anyhow, when I tried to use the toaster under generator power (not the same time as microwave), the toaster would not engage (stay plunged down...I tried another toaster, same thing so no the appliance itself). This seemed weird to me, as I thought the microwave would draw as much/more power than the toaster.

I then tried the CoolCat under generator power; the CoolCat ran fine with just the fan engaged, but as soon as I turned on the AC, the generator cut out; I tried the generator/AC again several times...same result every time.

So in summary:

- generator has worked perfectly for 3 years (powered all required functions)
- generator was worked harder than normal for a few weeks, still fine
- generator now will power the microwave, but not AC or plugin appliances

Has anyone had something like this happen to them...have any ideas/suggestions? As a non-mechanical guy, I was thinking that maybe the extra work the Onan performed has caused some sort of problem? Maybe the spark plugs are dirty and therefore it's not producing/putting out the necessary power? Really, I have no clue. lol

Any ideas/suggestions would be greatly appreciated.


M

[booster]

Originally Posted by Mean_Jeanne

Hello all:

So I just read a thread by "Old Pilot" (thanks for posting) and I'm having similar, but not exactly the same, problems with my Onan 2500, in that it's suddenly not providing enough power to run certain functions.

First off, I have a 2007 Roadtrek 170 P, with an Onan 2500 Generator (gas powered). The Onan was completely rebuilt a few years back, and it's been running perfectly since then...starts up fine, powers the microwave, plug-in appliances (toaster) and the CoolCat AC (I boondock with the 170).

I had an isolator problem in the spring and had to run the generator a lot more to charge the house battery, but it worked like a champ and still powered everything. I since rectified the isolator issue (thanks loads for your help "phantomjock"), and everything was still fine with the generator to power the aforementioned functions.

However, the last trip I took, I started the generator (all good) and it powered the microwave fine...although it did "sound" a little bit rougher?! Anyhow, when I tried to use the toaster under generator power (not the same time as microwave), the toaster would not engage (stay plunged down...I tried another toaster, same thing so no the appliance itself). This seemed weird to me, as I thought the microwave would draw as much/more power than the toaster.

I then tried the CoolCat under generator power; the CoolCat ran fine with just the fan engaged, but as soon as I turned on the AC, the generator cut out; I tried the generator/AC again several times...same result every time.

So in summary:

- generator has worked perfectly for 3 years (powered all required functions)
- generator was worked harder than normal for a few weeks, still fine
- generator now will power the microwave, but not AC or plugin appliances

Has anyone had something like this happen to them...have any ideas/suggestions? As a non-mechanical guy, I was thinking that maybe the extra work the Onan performed has caused some sort of problem? Maybe the spark plugs are dirty and therefore it's not producing/putting out the necessary power? Really, I have no clue. lol

Any ideas/suggestions would be greatly appreciated.


M

A bit confused as a 2007 170 should have a gasoline 2800 Onan in it.


With all of the older gas powered Onans, the first thing to look at is the fuel.


Did it sit for more than a couple of weeks with ethanol laced fuel in it?


Even for short periods that can reduce power and create surging under load.


The plugging from ethanol is progressive with each sit time until it starts to have a problem so a bunch of short times can be as bad as one or two long times sitting.