bobsallyh

KATOOM, do folks treat Yamahas and Hondas any better?

KATOOM

Absolutely.

Excluding the fact that any Honda/Yamaha generator we're talking about here is going to be of relatively current day stuff.....and is going to be built to accommodate today's fuel types. There are no permanent mounted factory Honda or Yamaha RV/trailer generators that I've heard of. Therefor the odds are that their "portable" Honda/Yamaha generators will be used for plenty of other odds and end chores throughout the year, instead of being jammed in the trailer storage compartment left to rot since the last camping season.

Even at that, the fact that they're portable means that, unlike a permanent mounted Onan, if they have any problems with their Honda/Yamaha generators they can easily drive it to a repair shop. So yeah, depending on how you want to look at it, the differences are apples and oranges.

Lastly, if you do a simple Google search for problems with either Honda or Yamaha generators, the abundant list of forums, websites, and youtube video's suggest that those so called impervious to problems generators can be just as problematic. And hey, coincidentally most problems are fuel related.

RobG

I finally got the carburetor cleaned. I ran it for 40 minutes in an ultrasonic cleaner (after fully disassembling it first), and also sprayed it out good afterwards with carb cleaner and flossed all small openings.

Upon reinstallation, the occasional black smoke issue is gone. It did, however, blow a lot of white smoke. It ran for several minutes producing power (nothing major), and then I turned on the AC and that killed it. I couldn't get a code out of it so I fired it up again. This time the exhaust was clean and it sounded nice. But just as I went inside to turn the AC on, the RPMs dropped way down and it started sputtering and blowing white smoke again, then died.

This time I was able to get a single code... 15. The Great Google says Underfrequency Fault (Engine governor unable to maintain rated frequency) whatever the hell that means. It goes on to say "reduce the load on the generator" which is funny since there was very little load on it to begin with.

So... still a carb problem or do I rip it out and sell it off for whatever I can get?

KATOOM

Two things.....

Be absolutely sure the AC is functioning because if its not then the load on the generator will be so great that either the AC breaker will pop or the generator will stall.

If the generator runs better with smaller loads applied, like the microwave, electric hot water heater, or any plugged in appliances, then it would seem that somethings wrong with the AC like a bad capacitor or locked compressor. An easy way to check the AC function is to plug the RV/trailer up to shore power of correct amperage plug.

Second, make sure the altitude adjustment on the carb bowl is correct because one time my generator would do something very similar and it turns out I forgot to change the altitude setting back to where I was currently running the generator. Lastly, hopefully you put the governor spring setting back in the correct position otherwise the engine wont run in the proper RPM range for the generator to make the correct voltage/amperage.

RobG

The AC is fine, I know that much... it's less than a year old and runs great on my 20A AC connection.

That spring... yeah I'm not 100% sure on it. I may need to take a pic tonight and post it to see if you think it's in the right place. I put it back where it made the most sense.

If that checks out, what's the next step? Had a guy offer me $300 for the thing, but that seems a bit lower than I was thinking.

KATOOM

But will the generator run fine while powering other electric devices? Thats worth knowing.....

RobG

We'll find out tonight. But this is the problem I was having before too... it'd run okay at very low load... at least for a little while, but once you load it up at all (e.g. microwave), it kills it... that's when I was getting Code 13 before. We'll see if that's what it still does.

KATOOM

I just went out today and exercised my generator and took a picture for you just in case you need some reference. I cant say whether or not your governor would sit in the "exact" spring position but if not I'm sure its going to be close. Hopefully it helps you out. Dont forget about that altitude adjustment too. Giving it a few turns back and forth to clean the jet inside can help dislodge varnish.

Also, if you even care, my protocol is to give the engine a one to two second crank knowing it wont fire immediately. Then I'll prime the fuel pump and listen for its proper operation. Kinda surprising how loud that little pump is, rattling away. Then when the fuel is pumping good and I can hear the bowl is filled, I'll crank the engine and it will start perfect. Give it a few minutes to warm and then turn the AC on. Let everything run for 15-20 minutes to fully exercise both the generator/engine and the AC unit. Then turn the AC off and let the generator/engine cool down for a few minutes running with no load. Then shut it down. Sometimes if its hot enough outside I'll even leave the cover off just to let it all cool down in there, just because I'm like that.

RobG

Thanks!!

I checked and my spring was set three slots farther to the right than yours. So I changed mine to be just like yours and fired it up. It fired up and idled pretty well... idle was a little erratic but nothing major. So I came in and turned on the AC. You could hear it load up a bit but it kept running. After about a minute, the RPMs dropped way down and it started blowing black smoke like it had before. This continued for 30 sec or so, then it cleared up, RPMs went back up and things continued. This repeated several more times.

Then I came in and turned off the AC, in the middle of one of the black smoke fits, but it made no difference. Then I turned on a space heater since it's chilly here today and the AC wouldn't have run much longer anyway, and 30 sec later it sputtered and died, again with a Code 15.

KATOOM

Kinda just sounds like you simply need to dial it in. Try moving the spring even more and see if it helps.

And just so I make sure to mention it again, mess with that altitude adjustment **** a little just to assure its not varnished up too.

All that said, are you positive the fuel tank has clean fuel in it? The fuel filter "could" be clogged and not allowing enough fuel to pass while under a load. Just a thought.

RobG

The fuel is good.. it runs nice 'n clear and has a bottle of Sea Foam in it as I recall. Plus I ran the test with 100% new gas a few months ago when it was doing this and nothing changed. We also pulled the fuel filter and it was running properly as well.

The air filter is clean, the fuel filter is fine, the altitude adjustment is fine too... I ran the whole bowl through the ultrasonic cleaner twice to be sure.

I'm really curious about the black smoke and why it does it so regularly... like clockwork. What the heck would cause that?

I wish I had another known-good carburetor to try on it. I also want to put fresh spark plugs in it. When we checked them in Moab a couple months ago, they were pretty carboned up, but we cleaned them up real well and reinstalled them since we didn't have replacements.

I suppose tonight is at least showing some progress, since last night it was all white smoke, now it's black. Hmm.

Onan really needs to make these things EFI. AND while I'm complaining, it should have its own starting battery instead of relying on the RV batteries.

Edit: Looks like replacement plugs are NGK BPR4EY, gap to 0.025. I'll pick some up tomorrow or Friday.

KATOOM

Black smoke means its running too rich for that momentary second and the cylinders are puking it all out. My generator will do the same thing upon starting if I let the fuel pump over prime the carb by holding the prime button for too long. But the more often I run it, the cleaner it tends to run overall.

Onan does make them in EFI models too, and even with diagnostic LED's. Probably for cost reasons you dont see them to often in your everyday RV/trailer. But nonetheless, they do make some pretty slick models which vary from diesel, propane, liquid cooled, fuel injection, etc...

And in regards to the generator starting battery..... I didnt care for the generator to share the two 6 volt house batteries either. So because the generator also doesn't charge the batteries (at least my model doesn't and you'd have to see if yours does, but likely not), I installed a third 12 volt battery dedicated to just starting the generator. I also installed a battery charger which connects only to that 12 volt battery which runs off the 110 power outlet in the storage compartment. That way when the trailer is plugged into shore power the additional charger assures that 12 volt starting battery is fully charged at all tiems, and when the generator is running it also powers the 110 outlet which keeps its own battery up. Works perfect and I ended up doing this years ago when I found my furnace drained the old house batteries overnight to the point where I couldn't start the generator in the morning. Since then I've reconfigured things to work right.....or at least work for what I need.

RobG

Hmm... okay so then something is causing the carburetor to go too rich... or maybe a bad choke? Starting to wonder if a new carburetor could be the answer.

KATOOM

Thats quite possible. I'd have someone turn the AC on while you watch for governor movement and choke actuator movement. I cant remember if the actuator powers to close or powers to open so you could "maybe" simply unplugging the actuator and see what happens.

Here's a copy of the manual for the 5500 models if it helps.

RobG

Thanks!! Maybe I can figure this thing out after all. If I don't have to pull it out, that'll be nice. Looks like a major PITA to remove.