Home » Public Forums » GMCnet » Like Maria, My Onan has lost its Governator (Issues with Onan Generator maintaining proper speed)
| Like Maria, My Onan has lost its Governator [message #128789] |
Sun, 05 June 2011 17:56  |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
I did about a week's worth of dry camping mid-May, and on the 2nd day my Onan generator seemed to lose it's ability to maintain the proper speed. Very disappointing considering I spent 2 weekends on it last fall, and it was running great when I put it away.
I tried to do the adjustment on the length of the rod between the governor arm, and the throttle on the carburetor, and the arm needed to be about 1" longer to get it to the right place. Being bored and in the woods, I cobbled together an extender for the rod and it didn't help a bit. The throttle would stay more or less in the same spot regardless of load. You could feel spring tension on the governor lever when the engine was revved, but it didn't seem to change with speed.
For my next dry camping experience, I took the plunge on a Yamaha suit case generator that I know I'm going to love, but hated to spend the money.
Trying to decide if I really want to tear into the Onan for yet another weekend. Looking at the manual, it appears there are 2 screws that hold a contact plate on to the shaft that comes out of the engine. I'm wondering if they came lose? Alternatively, they mention a pin that is pressed into the cam, that sometimes comes loose, and can't be reset without replacing the cam. One of those sounds easier to fix than the other.
Anyone experience anything similar? I'm trying to decide how long it's going to take before I tackle it, so that it can remain just one more repair from running really good.
Thanks
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
| Re: Like Maria, My Onan has lost its Governator [message #128800 is a reply to message #128789] |
Sun, 05 June 2011 19:10  |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
|
Senior Member |
|
|
Is the sail still in place and connected? Nothing is binding on the ball ends? Did you lubricate them?? Can't understand it's so simple a system. Did a plastic bag or something get sucked in to the air path????
John Lebetski
Woodstock, IL
77 Eleganza II
|
|
|
|
| Re: Like Maria, My Onan has lost its Governator [message #128803 is a reply to message #128800] |
Sun, 05 June 2011 19:24 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
John,
No binding, although I didn't lube things. But there is something disconnected, or at least very loose. They don't use air, like a lawn mower does. There are 10 metal flyballs, that work outwards from ramps in the camshaft sprocket. (Underneath the gear cover for the crank and cam gears). They push something called a governor cup outward, which acts on a governor yolk that attaches to the shaft and arm that protrude out of the top of the engine. (All this from the manual, not sure I actually want to see the gory details in person). It seems like perhaps that yolk might be loose, as it is retained by 2 screws. But, I could have lost my balls or even something worse. Looking for some easy answers, since I'm just not excited about tearing into it all again. (Although it would probably be a good time to throw on a Pertronix kit if I did.)
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
| Re: [GMCnet] Like Maria, My Onan has lost its Governator [message #128808 is a reply to message #128803] |
Sun, 05 June 2011 20:08 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
|
|
Unless dire things happen internally, those 10 balls ride in milled grooves
in the cam gear. The cup covers them. When the engine rpms increase, the
balls fly outward, causing the cup to move towards the cam cover. The shaft
that the governor arm is attatched to has a fork or as Onan calls it a yoke
that bears against the cup. The governor spring has to have sufficient
tension to force the cup back to rest when the engine is not running. The
yoke is fastened to the shaft with two small screws about the size of the
ones that hold a butterfly plate in place on a carburetor throttle. They
have been known to back out but not too likely, as they are staked in place
after being tightened. There is an oil seal on the top of the cam cover
where the shaft exits the cover. The only way to replace that seal is to
take out those screws. If that has been done to your onan, loose screws are
a possibility. When the engine is not running, the carb butterfly should be
wide open, when the engine starts, the effort from the governor balls is
balanced with the throttle spring. The more tension on the spring,
the faster the engine will run. As the load on the generator increases, the
rpm will slow slightly, and the throttle spring will open the throttle more,
increasing the rpm. Kinda like a tug of war between the governor effort and
the spring. There is a long threaded rod in the linkage with jamb nuts on
both sides of a piece of linkage. That is what should be adjusted to set the
rpm for the best voltage. If the voltage is 125-130 when there is no load on
the unit, that is about right. Under load, the voltage should be in the
range of 115-120 V AC.
If you still have problems, I will try to walk you through the adjustment
procedure.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Sun, Jun 5, 2011 at 5:24 PM, Craig Lechowicz <
craig.lechowicz@sbcglobal.net> wrote:
>
>
> John,
> No binding, although I didn't lube things. But there is something
> disconnected, or at least very loose. They don't use air, like a lawn mower
> does. There are 10 metal flyballs, that work outwards from ramps in the
> camshaft sprocket. (Underneath the gear cover for the crank and cam gears).
> They push something called a governor cup outward, which acts on a governor
> yolk that attaches to the shaft and arm that protrude out of the top of the
> engine. (All this from the manual, not sure I actually want to see the gory
> details in person). It seems like perhaps that yolk might be loose, as it
> is retained by 2 screws. But, I could have lost my balls or even something
> worse. Looking for some easy answers, since I'm just not excited about
> tearing into it all again. (Although it would probably be a good time to
> throw on a Pertronix kit if I did.)
> --
> Craig Lechowicz
> '77 Kingsley, Waterford, MI
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: Like Maria, My Onan has lost its Governator [message #128971 is a reply to message #128789] |
Mon, 06 June 2011 20:18 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
Jim,
Thanks so much for your detailed reply. Not only do you know your Onan governors, you can describe their operation and adjustment a heck of a lot better than the shop manual does.
I guess I'm slow, because I never quite got the description in the manual. Read yours and it all made sense at last. Turned out I was lengthening the adjustment rod in a situation when I should have been shortening it.
If it wasn't for accidentally putting the adjustment bolt at the end of the spring "someplace I wouldn't lose it" while up north, it was an easy repair. Not easy to drill that little spring hole through a bolt to make a new one, though.
At any rate, with the correct adjustment, I just got in from running different loads like 1 or 2 roof a/c's, water heater, inverter/charger and no load, and it seems to be holding voltage settings pretty well.
Of course, I'm still one repair away from having a great running Onan, as I noticed the exhaust pipe to manifold gasket was starting to leak . . .
For now, good enough, especially since I plan to give that new Yamaha a workout most of the time, instead.
Thanks again for your help,
Craig
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
|
|
| Re: Like Maria, My Onan has lost its Governator [message #129016 is a reply to message #128789] |
Mon, 06 June 2011 22:39 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
|
Senior Member |
|
|
| Craig Lechowicz wrote on Sun, 05 June 2011 15:56 |
I did about a week's worth of dry camping mid-May, and on the 2nd day my Onan generator seemed to lose it's ability to maintain the proper speed. Very disappointing considering I spent 2 weekends on it last fall, and it was running great when I put it away.
{snip}
Anyone experience anything similar? I'm trying to decide how long it's going to take before I tackle it, so that it can remain just one more repair from running really good.
Thanks
|
Craig, I can't help you on the Onan, but if by any chance you have the original Norcold swing motor compressor refrigerator, be very careful of the voltage and frequency of the generator. It can easily cause the compressor to fail in those original refrigerators.
Rob Allen
former owner of '76 x-PB
|
|
|
|
| Re: Like Maria, My Onan has lost its Governator [message #129056 is a reply to message #128789] |
Tue, 07 June 2011 08:20 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
Rob,
Thanks, I do have the original Norcold, probably mostly through a combination of stubbornness and cheapness, although it has some nice features as well.
And, I've read all your info on it several times, and remembered your comment about voltage/frequency sensitivity.
I'm not sure what the danger range is there, but I ran it for about a week plugged into an extension cord, after we got back, and it was starting to freeze my 2 litre of diet pepsi on the #2 cold setting, so doesn't seem to be the worse for wear.
My original Norcold inverter has failed, so I've been running it off my ProSine 2,000 watt pure sine wave inverter. But, apparently the big inverter isn't very efficient at low loads and standby, as it runs my 2-6 volt agm batteries pretty low after an overnight session. I hear a lot of people can go a weekend.
So, last week I ordered a bunch of stuff to more fully embrace your battery saving recommendations. I have a 120 v. to 24 volt, 3 amp transformer coming from AllElectronics. It's 24v. center tapped, but I think if I ignore the center terminal and just wire to the outer ones, I'll be okay?
I also ordered a 250 watt Samlex modified sine wave inverter from Don Rowe <http://www.donrowe.com/inverters/sam_250.html>. Hopefully, I haven't been spoiling my Norcold with the pure sine inverter, as I think the now dead original was sort of a modified sine wave. I plan to always power the Norcold through the small inverter, and use an automotive relay hooked through the thermostat to the power input of the inverter. Other than the compressor and thermostat, I won't be using any of the original Norcold electrics with this change. This should take the 50% of the time standby losses to zero and hopefully, improve the running inverter efficiency as well. I don't mind a little more loss when plugged in or on generator. And, the ProSine does a great job of charging/converting.
The always inverter approach should eliminate the concern over the Onan voltage fluctuation, although now that I have the suitcase Yamaha, I expect to mostly be using it. I hope to get all these parts wired in by the 24th of June and give it another dry camping test at the Mid-Ohio vintage races. (Assuming I fix some chassis engine issues as well).
Since you have done so much study of the Norcold, I wondered what you thought of this plan, and if you had any other tips or suggestions.
Thanks,
Criag
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
| Re: Like Maria, My Onan has lost its Governator [message #129085 is a reply to message #129056] |
Tue, 07 June 2011 11:04 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
|
Senior Member |
|
|
| Craig Lechowicz wrote on Tue, 07 June 2011 06:20 |
Rob,
Thanks, I do have the original Norcold, probably mostly through a combination of stubbornness and cheapness, although it has some nice features as well.
And, I've read all your info on it several times, and remembered your comment about voltage/frequency sensitivity.
I'm not sure what the danger range is there, but I ran it for about a week plugged into an extension cord, after we got back, and it was starting to freeze my 2 litre of diet pepsi on the #2 cold setting, so doesn't seem to be the worse for wear.
My original Norcold inverter has failed, so I've been running it off my ProSine 2,000 watt pure sine wave inverter. But, apparently the big inverter isn't very efficient at low loads and standby, as it runs my 2-6 volt agm batteries pretty low after an overnight session. I hear a lot of people can go a weekend.
So, last week I ordered a bunch of stuff to more fully embrace your battery saving recommendations. I have a 120 v. to 24 volt, 3 amp transformer coming from AllElectronics. It's 24v. center tapped, but I think if I ignore the center terminal and just wire to the outer ones, I'll be okay?
I also ordered a 250 watt Samlex modified sine wave inverter from Don Rowe <http://www.donrowe.com/inverters/sam_250.html>. Hopefully, I haven't been spoiling my Norcold with the pure sine inverter, as I think the now dead original was sort of a modified sine wave. I plan to always power the Norcold through the small inverter, and use an automotive relay hooked through the thermostat to the power input of the inverter. Other than the compressor and thermostat, I won't be using any of the original Norcold electrics with this change. This should take the 50% of the time standby losses to zero and hopefully, improve the running inverter efficiency as well. I don't mind a little more loss when plugged in or on generator. And, the ProSine does a great job of charging/converting.
The always inverter approach should eliminate the concern over the Onan voltage fluctuation, although now that I have the suitcase Yamaha, I expect to mostly be using it. I hope to get all these parts wired in by the 24th of June and give it another dry camping test at the Mid-Ohio vintage races. (Assuming I fix some chassis engine issues as well).
Since you have done so much study of the Norcold, I wondered what you thought of this plan, and if you had any other tips or suggestions.
Thanks,
Criag
|
Craig: You are right on track with your modifications. I ran mine on a Xantrex "modified sine wave" inverter with very good results. That inverter was only $25, but the unit had to be manually started (will not start just by connecting it to 12 volts) so I just left the inverter on 24/7 when out, and it worked very well. By always powering the refrigerator from the inverter, I avoided any voltage or frequency variations from generator starting or stopping. The PD 9160 I had would recharge the batteries very well when the generator ran. So, my power path was 12 Volts DC to 120 volts AC, to the new transformer which steps down to 24 volts AC for the swing motor compressor. Sounds inefficient, but it is not.
If your new inverter will "start" by just connecting it to 12 volts, your plan to have the inverter controlled by the refrigerator thermostat is fine. As I said, the inverter I had would not work that way.
I made one test using a simple "modified sine wave" inverter which apparently was a poor quality unit, and caused the noise level of the compressor to increase substantially, as well as the current draw. I expect your Samlex will be OK, but pay attention to the sound, and compressor case temperature. If either does not seem normal, do some further checking and get back to me.
Yes, if you have a center taped 24 volt transformer, just tape off the center line and use the outer ones that will result in a 24 volt output.
Glad things are progressing well, let me know if I can help further.
Rob Allen
former owner of '76 x-PB
|
|
|
|
Goto Forum:
Current Time: Mon Oct 14 15:27:59 CDT 2024
Total time taken to generate the page: 0.01066 seconds
|
GMCforum
Search
Help
Register
Login
Home
