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Genset only stays running in WARM weather!


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  #1  
Old 05-30-2011, 01:00:59 PM
onangeneratorhelp onangeneratorhelp is offline
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Exclamation Genset only stays running in WARM weather!

Let's get to it. I have an Onan Emerald One RV Genset with the following specs:
Model: 4BGEFA26100F
Serial: L890283440
AC Volts: 120
Amps: 33.3
Fuel: Gasoline
Phase: 1
Hertz: 60
Killowatts: 4.0
RPM: 1800
Battery: 12V

Now that I got all that out, I have an ongoing problem that I cannot solve. I have posted on these forums before, and a very generous guy gave me all the manuals for it... except I still cannot solve the BLEEP! problem! This RV genset is REALLY nice, and we love it when it's running. But here's the rub. It ONLY works in WARM weather (above 70 or 80 degrees F). Well, in the mountains, that is not always the type of weather that you get. It starts, and runs, but dies as soon as you let go of the switch. If you were to supply power or start the motorhome engine so that it did not drain the batteries, you can hold the start switch down (the starter is disengaged at this point) and hold the throttle down, it will stay running once it's all nice and warmed up. I have done all the tests in the book. My regulator works. My control board works. The brushes are good. I have checked the LOP (Low Oil Pressure) switch and it checks out fine. I have checked ALL the wires in the control box and they are all connected and not frayed, cracked, exposed or broken. I have also checked for resistance between ground and the genset, and there is little resistance, so the ground is good. Also, I know this is a huge post but I figured I would see if this peice of info helps. If you're holding the start switch down to warm it up, it will make a metal clunking noise from the generator portion of the unit. It will clunk every so often as if something is trying to catch on it. Then, after it is warmed up, you hear it clunk, and then it catches and you can actually hear it start to generate and then it stays on. Idk what is making this clunking noise in there , but I know it is relavent to the problem. What can only cause it to stay running once the switch is released in warm weather, or if the genset has been warming up for 10 or so mins? Thanks for any help! If I cannot fix it, I am going to have to get rid of the genset as is, and go buy a crappy, noisy external generator so we can have reliable power. Sorry for the long post! I would like to have this fixed by Friday, the 3rd of June, for a trip in the mountains!
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Old 05-30-2011, 01:20:34 PM
kg5388 kg5388 is offline
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Default Re: Genset only stays running in WARM weather!

is it damp there when it's cool?
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Old 05-30-2011, 01:28:04 PM
Ben Clarke Ben Clarke is offline
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Default Re: Genset only stays running in WARM weather!

Not a expert at anything but I have read here that a propane regulator will over time collect oil residue. Your regulator could be gummed up and at warmer temps be loose enough to work but requie "warming up" to work at lower temps.
This is just a guess.
Ben
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Old 05-30-2011, 01:35:55 PM
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Default Re: Genset only stays running in WARM weather!

Since this is a gasoline generator, i know on some generators it has an elctric choke that is only engaged when you press the start switch. When you let off the switch, the choke opens back up. Does this unit have an electric choke, or is it operated off a heat riser? If its a heat riser type, it can be adjusted where it stays closed a little longer. Or you could install a manual choke cable.
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Old 05-30-2011, 02:04:34 PM
onangeneratorhelp onangeneratorhelp is offline
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Default Re: Genset only stays running in WARM weather!

Quote:
Originally Posted by kg5388 View Post
is it damp there when it's cool?
No it is not. I live in Utah, it's really dry even when it's raining.

Quote:
Originally Posted by Ben Clarke View Post
Not a expert at anything but I have read here that a propane regulator will over time collect oil residue. Your regulator could be gummed up and at warmer temps be loose enough to work but requie "warming up" to work at lower temps.
This is just a guess.
Ben
This engine is a gasoline powered engine. Thanks for you help though!

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Originally Posted by JKWidener View Post
Since this is a gasoline generator, i know on some generators it has an elctric choke that is only engaged when you press the start switch. When you let off the switch, the choke opens back up. Does this unit have an electric choke, or is it operated off a heat riser? If its a heat riser type, it can be adjusted where it stays closed a little longer. Or you could install a manual choke cable.
How do I check the chock heater? It has both an electric choke, and a lever that switches it from "winter" or "summer." I assume on the winter position, it sucks in air from the exhaust manifold to aid in warming up. But the engine does run. I can rev it with the throttle and everything while I hold the start switch down so it does not die.
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Old 05-30-2011, 02:26:14 PM
kg5388 kg5388 is offline
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Default Re: Genset only stays running in WARM weather!

the reason I asked if it was damp is there was a problem with the brush holder bolt shorting out to the brush connection due to moisture condensing on the brush block.

Now you need to check to see if it's making ac voltage during the time it cranks but dies when you let go of the switch.
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Old 05-30-2011, 02:30:19 PM
MBB MBB is offline
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Default Re: Genset only stays running in WARM weather!

Sounds like the electric choke . Two different kinds. Look in your manual for adjustment. If it had been removed its a pain to put back. Once you have done it a few times not a problem. Take a picture if possible
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Old 05-30-2011, 02:54:54 PM
onangeneratorhelp onangeneratorhelp is offline
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Default Re: Genset only stays running in WARM weather!

Quote:
Originally Posted by kg5388 View Post
the reason I asked if it was damp is there was a problem with the brush holder bolt shorting out to the brush connection due to moisture condensing on the brush block.

Now you need to check to see if it's making ac voltage during the time it cranks but dies when you let go of the switch.
I am making 30.5 volts DC and 60 volts AC at the brushes when it's doing this.

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Originally Posted by MBB View Post
Sounds like the electric choke . Two different kinds. Look in your manual for adjustment. If it had been removed its a pain to put back. Once you have done it a few times not a problem. Take a picture if possible
I have a question however, how does this cause the engine to stop running when the switch is released? I am curious? Have you seen the choke cause this condition in the past on this unit? Where does the choke get it's power anyhow?
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Old 05-30-2011, 03:11:38 PM
Douglas123 Douglas123 is offline
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Smile Re: Genset only stays running in WARM weather!

If your genset is not making Proper ac voltage, as soon as you release the stop switch the engine will loose b+ and stop. If your genset is making proper ac the ac run relay will pick up and alllow the unit to continue running. Probably have a non functioning rectifier. Cute little square puppy with four wires and a screw mounting it in the center locate in the backside of the control panel. Make sure you are making proper ac voltage. Check top side of breakers not the output side. sometimes breakers can lead you in the wrong direction.
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Old 05-30-2011, 03:33:12 PM
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Default Re: Genset only stays running in WARM weather!

Sorry missed the part about it not continuing to run unless the switch was down. Still souds like a choke problem plus something else. What voltage do you have at the choke?
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Old 05-30-2011, 03:34:50 PM
arkieoscar arkieoscar is offline
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Default Re: Genset only stays running in WARM weather!

It may have brushes sticking in their holders when cold. Easy to clean the whole assembly and see if that stops the clunking and lets it generate proper voltage to keep it running.
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Old 05-30-2011, 04:24:54 PM
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Default Re: Genset only stays running in WARM weather!

Its a choke issue. When you are holding in on the start button, the choke is activated "closed", when you release the start button, the choke automatically goes to the "open" position. I bet their is some dirt in a jet on the carburetor also not allowing the propper fuel supply after the choke is released.
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Old 05-30-2011, 08:23:19 PM
onangeneratorhelp onangeneratorhelp is offline
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Default Re: Genset only stays running in WARM weather!

So I guess I found the problem, sorta. It's either the voltage regulator, or the control board. Here's what I did. I took both units off the genset, brought them inside, cleaned them up a bit, then got my heat gun and heated both units up until they were quite warm to the touch, but not unbearable to hold. Then I went back out to the genset, hooked them both back up, cranked it and it and it immediately started generating and I was able to release the start switch and have it continue to run. Now, since I heated both, which one of these do you think is the problem? I re-soldered all the joints on the board a few days ago and this did not solve the issue. I am hoping the control board is bad VS the regulator considering the price tag on the regulator but maybe I should replace both to just be wise. *sigh* $320.

Quote:
Originally Posted by Ben Clarke View Post
Not a expert at anything but I have read here that a propane regulator will over time collect oil residue. Your regulator could be gummed up and at warmer temps be loose enough to work but requie "warming up" to work at lower temps.
This is just a guess.
Ben
I did notice in the manual for this problem in the manual. If oil or anything is getting into the regulator or the carburetor passages, then you need to make sure the PCV system is working well, and that you have new filters on your gas supply going into the unit. The oil can clog up the passages and cause horrible performance. The manual states that LPG comes into the system as a vapor, and not a liquid and it disipates when shut down, so there should be no reason for the oil in the fuel system unless something is wrong.
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Old 05-30-2011, 08:30:47 PM
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Default Re: Genset only stays running in WARM weather!

Check your crankcase vent, it has something similar to a reed valve in it, if they get dirty and stick, it will cause oil to pass into the breather tube and into the carburetor. The crankcase filter/vent is how the crankcase breathes...
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Old 05-30-2011, 08:42:55 PM
Rod Fielder Rod Fielder is offline
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Default Re: Genset only stays running in WARM weather!

i think i would sell it to someone who lives in florida where it's warm
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Old 05-30-2011, 08:49:51 PM
onangeneratorhelp onangeneratorhelp is offline
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Default Re: Genset only stays running in WARM weather!

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Originally Posted by Rod Fielder View Post
i think i would sell it to someone who lives in florida where it's warm
Ha ha ha ha!
That was my laugh of the day. That was awesome. Thanks for that. In all honesty, do you think it is worth it to spend $340 plus shipping on a new regulator and control board? Or should I sell it as is for $300 and go buy an external unit? I have no clue how much one of these units are worth working...
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Old 05-30-2011, 09:18:33 PM
K D Redd K D Redd is offline
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Default Re: Genset only stays running in WARM weather!

Go to a electronics supplier and buy a can of Freeze Spray. Once you have the generator running, uses the Freeze Spray on each board to see which causes the engine to stop.

Kent
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Old 05-30-2011, 09:26:42 PM
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Default Re: Genset only stays running in WARM weather!

” Now, since I heated both, which one of these do you think is the problem?”

How about heating only one (use the heat gun on an extension cord) if this works you found it and only need to replace one

Keith
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Old 05-30-2011, 10:42:21 PM
kg5388 kg5388 is offline
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Default Re: Genset only stays running in WARM weather!

www.flightsystems.com they are cheaper and have a better warranty than onan parts.
They also will check out your boards for proper operation I've been told.

check the voltage at the breaker during cranking. put one lead to metal casing and the other to the back side of the breaker. If it has 120vac at the breaker then the voltage reg is doing its job.

check the sense leads to the control board and make sure they are connected to the control board correctly

need to know part number of control for proper trouble shooting step as there were several boards in use at the same time

on most old BGE the B1 and B2 windings feed the elect choke and P1 and P7 on the control.
others the sense lead goes to L1 and L0 terminal strips
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Old 05-30-2011, 11:20:01 PM
onangeneratorhelp onangeneratorhelp is offline
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Default Re: Genset only stays running in WARM weather!

Quote:
Originally Posted by kg5388 View Post
www.flightsystems.com they are cheaper and have a better warranty than onan parts.
They also will check out your boards for proper operation I've been told.

check the voltage at the breaker during cranking. put one lead to metal casing and the other to the back side of the breaker. If it has 120vac at the breaker then the voltage reg is doing its job.

check the sense leads to the control board and make sure they are connected to the control board correctly

need to know part number of control for proper trouble shooting step as there were several boards in use at the same time

on most old BGE the B1 and B2 windings feed the elect choke and P1 and P7 on the control.
others the sense lead goes to L1 and L0 terminal strips
Sounds good. Coincidentally, that is where I am getting my replacement parts from. It's $129 for the control board part #300-3056 and $200 for the regulator part number 305-0782.

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Originally Posted by RETCPO View Post
” Now, since I heated both, which one of these do you think is the problem?”

How about heating only one (use the heat gun on an extension cord) if this works you found it and only need to replace one

Keith
I am waiting until tomorrow to do it. Cause it's still warm. I know it seems like captain obvious that's something I should not have asked but I did anyhow
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