Older Yamaha Generator repair help request

[tri5ron]

Hello All,
It's been a LONG time since I have visited this forum, but I do often think about it and have sent several RVer's here over the years.

My life's situation has changed dramatically, and I am now living with my aging mother, trying my best to to assist her in her needs. It can sometimes be quite challenging, but we strive for the good times and happy days.

We live in a gated Senior's community, which has a RV storage lot within the community, as well as a RVer's "Club" where many residents get together for group campouts at various destinations.

I have become quite involved with the daily operations and tasks involved with the RV lot, and have come to be known as the " Resident RV Handyman", hahaha.

I will basically help anyone who needs it, do some minor repairs, and a few major ones too), and generally just try to be a Good Neighbor to many of the people who may not be physically capable or knowledgeable in general upkeep, maintenance, or repairs on their rigs.


I have recently acquired an older Yamaha EF1000 generator. it is from around the mid 1990's, and is sometimes called "the Blue Cube". It had been sitting neglected and unused for several years.

I figured it would need some attention (naturally). I poured in a little fuel, figuring I would let it sit a few days to opefully dissolve some of the varnish that was most probably in the tank and/or carb.
Well,... the fuel just ran right out onto the ground. no surprise, right ?)

OK,... so off with the body panels/case, to see what we've got.
The fule line was cracked, (no surprise there).
SOooooo, I pull the tank, give it a triple dose of rust dissolver, with through rinse and cleaning, new fuel line and fuel filter, drain, flush the crankcase, refill with fresh oil, give it a couple of pulls and she fires right up !
YAY !
She runs BEAUTIFULLY ! Smooth, clean, no smoke, no sputtering, idles great, quiet,... I'm in Heaven ! I'm never THAT lucky !, but it is idleing like a champ and sounds GREAT !

BUT,.... (of course there is a "BUT", right ?)
... the voltage gauge shows nothing, the "AC (green) Power Light is not on, and there is no power being generated.
I plug in a small power tool (Dremmel motor),... nothing. then I try a small fan, and a standard drop light.
She's not making any power. zip, nada, nuttin'

Ok, so I'm 99% sure IDID NOT pull any connections loose when I had all the covers off, but I WILL double check that when I open it back up. It DID Look pretty darn clean and un-abused inside when I had it open the first time, and I did not see anything particularly obvious as a failed component.

So is there any of you here, who are Power Generating Genius's ?,... and knows something about these old genny's ?

The thing actually looks VERY well built, and quite a Quality product.

It is Made in Japan,.... By YAMAHA, and not some Chinese knock-off.
The Model is EF1000
I will take some pics in the next few days, once I get it opened back up.
I would greatly appreciate any help or suggestions on what to look for, test for, or where I can find someone knowledgeable to get suggestions from. I really would like to use this genny as a small power source for my little "quasi-Shop", (my 24' car hauler trailer), stuffed full of tools and "stuff". I have it in the RV storage lot here where I live and help the older folks here when they need help with their rigs.

It's kind of my little "Man-cave", and it has no power available to it. it is what I work out of, so it would nice just to be able to power a bench grinder, or small drill press, or whatever small power tool necessary.

Any help or suggestions appreciated,
Thanks,
Cheers,
Ron

[Grit_dog]

Thanks for those that shared this. Learn something new every day!

To the OP, sounds similar to what my FIL has done for the last 10 years or so. He became known as the neighborhood handyman (houses not rvs) To the point he was working almost full time and hired another resident or 2 that were handy to lighten the load. Had more work than he could do. Amazing what being honest, fair AND mechanically inclined will get ya.
They're moving this summer, built a new house in NV and the whole subdivision is upset, lol!

[2oldman]

tri5ron wrote:
Maybe someday that knowledge will come in handy to save another sole (soul) some unnecessary repair costs.

You should go back to the other forum and share this.

[gbopp]

Easy, cheap fixes are always the best type of repair. 🙂
Enjoy your travels and your generator.

[azrving]

You're welcome and yes, run it for a few hours with a load.

[MrWizard]

i would give a (2) hr run with a medium to high load

the idea is to get the armature saturated, you want to re-magnetize the iron corn in the generator field, which is the armature, in an A/C generator

after that it should be could for months or even a year

[tri5ron]

sorry,
double post

[tri5ron]

YAY ! You guys are GRRREAT !

I watched a couple of youtube videos on Flashing the generator with a drill or hand grinder and gave it a try.

I used a large Dewalt 90 degree hand grinder and gave it several spins.
At first it did not seem like anything was going to happen and I was getting a little discouraged. I tried for about 4 or 5 minutes and was about to give up, thinking there must be something more involved. Frustrated, I gave it a couple of more tries by rolling the wheel of the grinder across some plywood quickly and WA-LAAA ! ! ! It Worked ! the generator's power light came on, the voltage meter was registering 120v, and the grinder powers up just fine !
I am a happy HAPPY man !

I let it run for about ten minutes, and did a bit of grinding with my small Dremmel Tool. I then turned the genny off and back on a few times, and all seems well.
I then let it sit, turned off for about 4 or 5 minutes, and started it back up.
This time, after I fired it up, it did take a few extra seconds, (maybe 20-30 seconds)before the power light and voltage meter showed power output.
So I guess my next question is,
Should I now run it for an extended period of time? under load ? Heavy load, or light load ? or does this not matter now, and I should expect the field to remain excited for a reasonable amount of time now ? (Days/weeks ??)
I've always known that any generator needs to be run under load periodically to keep it in good operating order,...
.... but I did not know WHY.
Now I do ! YAY !

THANKS SO MUCH for the tip, I'll never forget that one.
Maybe someday that knowledge will come in handy to save another sole some unnecessary repair costs.

Happy trails to all.

[tri5ron]

gbopp wrote:
If you want more info, Google 'flashing a generator.'

I'll check that out right now.
Thanks !

[tri5ron]

2oldman wrote:
Try the Yamaha gen fan club.

The first post is your same problem.

Haha, Thanks.
Yes, that is me on there. I posted that after surfing the web for info and found that forum. I have not received any replies yet, and then thought I'd "come home" to the ORF, and see what some of the fine folks here might suggest.
Cheers !

[gbopp]

If you want more info, Google 'flashing a generator.'

[2oldman]

Try the Yamaha gen fan club.

The first post is your same problem.

[azrving]

I dont know how that stator/rotor system is designed but there may be one trick that will sometimes work on standard 3600 rpm generators. Plug a drill motor into it and hold the drill trigger on and twist the chuck to manually spin the drill motor. Sometimes after sitting, generators will lose their residual magnetism in the rotor. Twisting the drill motor will sometimes excite the system enough for it to start putting out. Costs nothing to try.