ONAN adjustment help

[JohnEd]

I have a NH 6.5KW gas Onan.  Hasn't been run in years.  When I fired her up she went straight to 100 volts and held nicely.   DRAT!

I remember that I am to turn in the mix screw under the card till I just see the throttle barely start to move and then back off a half turn.  That is the mix.  I have never adjusted the volts....how do I do that?  How do I verify the 60 cycle spec?

Thank you,

John

[WEC4104]

As far as verifying the 60 Hz is concerned, if you do not already have anything to check the frequency, you might consider adding the "Kill-A-Watt" tool to your collection.  It measures the electical frequency, as well as several other electrical characteristics.  Somebody mentioned this item a couple months back, and for $40, I've been thinking about picking one up myself.

Link:  http://the-gadgeteer.com/2003/12/23/kill_a_watt_electric_usage_monitor_review/

[Ncbob]

Hi John,

You have a fine little unit in that NH, it was the backbone of the RV industry for years.

Unfortunately the generator is always the forgotten componant in our persuit of the ultimate RV experience.
They need to be run at least once a month with some sort of load to make them work to cook out the moisture from the generator end. Me?  I'm as guilty as everyone else...I don't do it often enough.......

There is no voltage regulator in your generator. It has a compound winding in the generator end which acts as both a starter and generator. The worst damage you could do to the business end is to ask it to crank without a fully charged battery.

Considering all things being equal, points and plugs should be part of your Preventive Maintenance Program, voltage is controlled and interlocked with engine RPM's. It needs to run at 1800-1830 RPM's
(no load) in order to give you 60-61 cycles. The voltage will come up automatically within specs.
DO NOT OVER SPEED THIS UNIT! It gets expensive because the Armature will grow and collide with the Field.

A Vibrating reed meter will lead you to the proper RPM. You don't have to connect it electrically, just place it on the engine and it will respond to a Frequency reading. The Fluke 72 has the ability of reading both voltage and frequency.  Do NOT exceed  61 Cycles (no load) and you'll be fine.

Point setting is .018-.022 and Plug setting is .025. Timing will be OK with the proper point setting.

Hope this helps.

NCbob

[John316]

John,

I didn't read enough to see if this was what you wanted, however, I remember somebody saying that if you take a old analog clock (I don't think it could be digital), and check the seconds on it. When you are at 60hz, then the seconds will be right on.

God bless,

John

[JohnEd]

Thanks Guys.  Wish I had pics but I feel better about tinkering.

The cable that runs from the front to the rear to power the starter is a "bad" circuit.  My 12.6 drops to 8 when it cranks.  i must fix that, I know.  It has always started up quickly.  But, thanks.....I needed to up that priority.

I rebuilt the carb many years ago and while that didn't improve anything, it did run smoothly after I finished.  Given that it sits at 100 V without load, and that that is way off for her, I think I will go thru the carb again before I start adjusting.

You all have been very helpful and again, thanks.

John

[Van]

I just fired up my CCK 5.5 Onan the other day,still running good ,but the ac voltage with no load is at 135v,is that normal?I'm no electrician,but isn't 135v a bit high?  

[JohnEd]

Van,

We have the same problem but in reverse.  YES!  To many volts is just as bad as not enuf.

The carb controls the speed and voltage.  When I put my units up I used to run them dry of fuel.  I would then let it siphon the carb full of laquer thinner and then let it run itself out of fuel again.  That left the carb clean and dry so it didn't build up any junk.  I know  forgot to do that last time and I think I am paying for it.  Works for lawn mowers, also.  Gasoline in the carb bowl or anywhere else in th fuel system will turn on you if left for many months....let alone years.

John

[Van]

JE,thanx. So lowering the engine speed,will lowers the volts,got it thank you sir.I'll take a look at her in the morning,there is a rod attached to the throttle shaft,looks like it goes to the govenor,is this where the speed adjusted?I will take a photo of this thing tomorrow to post,thanks again.

   Van

[garhawk]

Hi John Ed,

     Here is one way to set your Onan (or other brand) to the proper rpm and voltage output.

     You will need an analog 120v clock with a 'second' hand.  The clock needs to be reasonably correct (within a couple of seconds).  Also needed is an accurate stopwatch.

     Start your generator, plug the clock into a 120v outlet supplied by the generator and, using the stopwatch as a referee, read the elapsed seconds on the clock face at the end of one minute.  If the elapsed time is less than one minute on the clock face, increase the rpm of the generator.  Should the clock face reading be more than one minute, the generator rpm should be decreased.

     Continue the process until the clock and stopwatch agree.

[buswarrior]

Kill-a-Watt at Newegg for 19.99

http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001&Tpk=kill%20a%20watt

for the Canadian site, change the .com to .ca - no border related fees.

I bought two when this came up earlier this year.

Measures amps, volts, hertz, watts and kilowatts consumed since plugged in.

A GREAT device for measuring the loads of the stuff you want to put in the coach, so you may plan your electrical system with more confidence on the real, longer term load/duty cycle.

For example, right now, here at home, the coffee machine with the internal tank is running at 3/4 of an amp and 95 watts on the counter with the burner on, 35 watts and 1/3 amp burner off, water tank heater loafing. I did not take note of when the power went off and reset it last, but it is showing 24 kilowatts of power consumption since that time.

A plan for a boondocking marathon could easily be ruined by not knowing about this little parasite!

And it will let you dial in the generator hertz, and check it, anytime you want, instantly.

Thank you Kill-a Watt!

happy coaching!
buswarrior

[JohnEd]

BW,,

I showed the "little woman", every bit of 5'1" soaking wet, your suggestion about the Kill-A-Watt monitor.  She said, in an unkind tone that challenged my intellectual acumen, "don't you remember my bringing one of those home from the library,FOR FREE, for you 6 months ago?  My snappy retort was "Duh, Uh Uh".  Went down hill from there.  Seems I have one of those and will shortly be putting it to good use.

Thanks all for bring that up.  Its good news...don't tell my wife I said that

John

[tomhamrick]

Ordered one from Radio Shack today for $25.00 and free shipping.

[Len Silva]

BW,,

I showed the "little woman", every bit of 5'1" soaking wet, your suggestion about the Kill-A-Watt monitor.  She said, in an unkind tone that challenged my intellectual acumen, "don't you remember my bringing one of those home from the library,FOR FREE, for you 6 months ago?  My snappy retort was "Duh, Uh Uh".  Went down hill from there.  Seems I have one of those and will shortly be putting it to good use.

Thanks all for bring that up.  Its good news...don't tell my wife I said that

John

You're lucky John,  Mine only remembers things I said or did thirty-five years ago.

[Van]

alrighty,got the voltage back down to 120.5v,still fluctuates a bit ,but seems to maintain it even with a load on it. This unit I have has been monkeyed around with by the PO obviously,as there were wires disconnected from the board and left there dangling like a Sherlock Holmes mystery LOL,I'll have some video of the volt fluctuations up soon and you be the judge as to whether it is stable enough to use for the roof top ac's.thanky

[Van]

the generator next to the portable fuel tanker
Onan video 0001
I think a final adjustment on the control rod hopefully will trim it out nicely.Seems every time I start it up the volage is off by maybe a half a volt,is it that much of a big deal? checked the voltage in our wall plates at home and it read 122v and some change,so I will assume if the genny output is set some where in between 120v and 122v that I am good to go? Please go easy, I am no electrician by any means LOL  so let 'em rip' and thank you for the help