more Onan troubles, 6KW

S

steve southworth

New member
Jul 17, 2007
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I'm having an Onan problem that is driving me nuts. Nothing I have done has solved the problem, or even helped.

I have taken the "engine trouble shooting guide" from the manual and listed out all the items mentioned that can cause my problems. Also listed are
reason each item may not apply, or actions taken. Please take a look at it and see if anything stands out to you. If I can't get the damn thing
running I'm hoping to borrow a known good carb to test install. If the problem is still there I will know for sure the problem is not the carb.
Obviously if it runs OK then the problem is the carb. If the carb, the mystery is still there. However when the book says the problem could be too
lean or too rich how do ya figger that out. Also which system is the problem, idle mix or power mix?

Also a good friend has taught me a very useful phrase. JUST SHOOT ME!

ONAN

PROBLEMS
Backfire at carb
Engine stops after very short run (less than one minute)
Governor hunting (suspect this is because of misfire or power loss)
Misfiring
choke has to be manually operated to get it started


INDICATED CAUSES

IGNITION SYSTEM
IGNITION TIMING WRONG
unlikely-pertronix ignition
WRONG SPARK PLUG GAP
new plugs gapped to 0.020 autolite 216
WORN POINTS OR IMPROPER GAP SETTING
Pertonix
BAD IGNITION COIL
Coil was marginal. swapped out for a good one (no change.)
FAULTY SPARK PLUG WIRES
wires tested good, swapped out for known good (no change)

FUEL SYSTEM
OUT OF FUEL
pump flow and pressure test good
LEAN FUEL MIXTURE
RICH FUEL MIXTURE OR CHOKE STUCK
choke not stuck
ENGINE FLOODED
POOR QUALITY FUEL
ran with external fuel tank with fresh fuel, no change
DIRTY CARB
carb cleaned and rebuilt, (some question about rebuild), however no change
DIRTY AIR FILTER
air filter removed, no change
DIRTY FUEL FILTER
new filter, no change
DEFECTIVE FUEL PUMP
pump flow and pressure test good

INTERNAL ENGINE (when engine finally starts runs good until it quits)
WRONG VALVE CLEARANCE
BROKEN VALVE SPRING
VALVE OR VALVE SEAL LEAKING

COOLING SYSTEM
POOR AIR CIRCULATION
cooling air flow not blocked
runs same rolled in or out of drawer
DIRTY OR OILY COOLING FINS
with cylinder head covers off fins are observed to be clean
BLOWN HEAD GASKET
no noise or exhaust gasses in discharge cooling air.

THROTTLE AND GOVERNOR
engine has same problems with linkages disconnect and controlling manually
LINKAGE OUT OF ADJUSTMENT
LINKAGE WORN OR DISCONNECTED
linkages checked OK for connection
GOVERNOR SPRING SENSITIVITY TOO GREAT
LINKAGE BINDING
linkage checked to be freely operating and properly lubed

I'll be going over this list with a highlighter seeing if I can make more sense of where the problem is. I would like to have another set of eyes to
look at this. I could be having some type of blindness that prevents me from seeing the problem

SteveS (going nuts in Palmyra)

P.S. the spouse is very unhappy right now. This problem has caused us to miss Amana. The phrase "happy wife, happy life" is not in operation at this
time.
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
 
Here’s what I did

Got rid of the demom fuel

http://gmc49ers.blogspot.com/2015/09/onan-gmc-propane-conversion.html

On Sun, Sep 23, 2018 at 6:02 AM Steve Southworth
wrote:

> I'm having an Onan problem that is driving me nuts. Nothing I have done
> has solved the problem, or even helped.
>
> I have taken the "engine trouble shooting guide" from the manual and
> listed out all the items mentioned that can cause my problems. Also listed
> are
> reason each item may not apply, or actions taken. Please take a look at
> it and see if anything stands out to you. If I can't get the damn thing
> running I'm hoping to borrow a known good carb to test install. If the
> problem is still there I will know for sure the problem is not the carb.
> Obviously if it runs OK then the problem is the carb. If the carb, the
> mystery is still there. However when the book says the problem could be too
> lean or too rich how do ya figger that out. Also which system is the
> problem, idle mix or power mix?
>
> Also a good friend has taught me a very useful phrase. JUST SHOOT ME!
>
>
> ONAN
>
> PROBLEMS
> Backfire at carb
> Engine stops after very short run (less than one minute)
> Governor hunting (suspect this is because of misfire or power loss)
> Misfiring
> choke has to be manually operated to get it started
>
>
> INDICATED CAUSES
>
> IGNITION SYSTEM
> IGNITION TIMING WRONG
> unlikely-pertronix ignition
> WRONG SPARK PLUG GAP
> new plugs gapped to 0.020 autolite 216
> WORN POINTS OR IMPROPER GAP SETTING
> Pertonix
> BAD IGNITION COIL
> Coil was marginal. swapped out for a good one (no
> change.)
> FAULTY SPARK PLUG WIRES
> wires tested good, swapped out for known good (no
> change)
>
> FUEL SYSTEM
> OUT OF FUEL
> pump flow and pressure test good
> LEAN FUEL MIXTURE
> RICH FUEL MIXTURE OR CHOKE STUCK
> choke not stuck
> ENGINE FLOODED
> POOR QUALITY FUEL
> ran with external fuel tank with fresh fuel, no
> change
> DIRTY CARB
> carb cleaned and rebuilt, (some question about
> rebuild), however no change
> DIRTY AIR FILTER
> air filter removed, no change
> DIRTY FUEL FILTER
> new filter, no change
> DEFECTIVE FUEL PUMP
> pump flow and pressure test good
>
> INTERNAL ENGINE (when engine finally starts runs good until it
> quits)
> WRONG VALVE CLEARANCE
> BROKEN VALVE SPRING
> VALVE OR VALVE SEAL LEAKING
>
> COOLING SYSTEM
> POOR AIR CIRCULATION
> cooling air flow not blocked
> runs same rolled in or out of drawer
> DIRTY OR OILY COOLING FINS
> with cylinder head covers off fins are observed to
> be clean
> BLOWN HEAD GASKET
> no noise or exhaust gasses in discharge cooling
> air.
>
> THROTTLE AND GOVERNOR
> engine has same problems with linkages disconnect and
> controlling manually
> LINKAGE OUT OF ADJUSTMENT
> LINKAGE WORN OR DISCONNECTED
> linkages checked OK for connection
> GOVERNOR SPRING SENSITIVITY TOO GREAT
> LINKAGE BINDING
> linkage checked to be freely operating and
> properly lubed
>
>
>
> I'll be going over this list with a highlighter seeing if I can make more
> sense of where the problem is. I would like to have another set of eyes to
> look at this. I could be having some type of blindness that prevents me
> from seeing the problem
>
> SteveS (going nuts in Palmyra)
>
> P.S. the spouse is very unhappy right now. This problem has caused us to
> miss Amana. The phrase "happy wife, happy life" is not in operation at this
> time.
> --
> Steve Southworth
> 1974 Glacier TZE064V100150 (for workin on)
> 1975 Transmode TZE365V100394 (parts & spares)
> Palmyra WI
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://bdub.net/gmcmotorhome.info/
Alternator Protection Cable
http://bdub.net/gmcmotorhome.info/APC.html
 
Steve,
The need to apply choke, combined with a backfire indicates fuel starvation.

Have you tried playing with the fuel mixture screws?

It is very possible that the carb has a blocked passage that was not corrected with your rebuild kit. There are several tiny passages that can be blocked by dirt, corrosion, or varnish.

Had the genset been running well upto a specific event?

Les Burt
Montreal
'75 Eleganza 26'

>
> Here’s what I did
>
> Got rid of the demom fuel
>
> http://gmc49ers.blogspot.com/2015/09/onan-gmc-propane-conversion.html
>
>
>
> On Sun, Sep 23, 2018 at 6:02 AM Steve Southworth

>
>> I'm having an Onan problem that is driving me nuts. Nothing I have done
>> has solved the problem, or even helped.
>>
>> I have taken the "engine trouble shooting guide" from the manual and
>> listed out all the items mentioned that can cause my problems. Also listed
>> are
>> reason each item may not apply, or actions taken. Please take a look at
>> it and see if anything stands out to you. If I can't get the damn thing
>> running I'm hoping to borrow a known good carb to test install. If the
>> problem is still there I will know for sure the problem is not the carb.
>> Obviously if it runs OK then the problem is the carb. If the carb, the
>> mystery is still there. However when the book says the problem could be too
>> lean or too rich how do ya figger that out. Also which system is the
>> problem, idle mix or power mix?
>>
>> Also a good friend has taught me a very useful phrase. JUST SHOOT ME!
>>
>>
>> ONAN
>>
>> PROBLEMS
>> Backfire at carb
>> Engine stops after very short run (less than one minute)
>> Governor hunting (suspect this is because of misfire or power loss)
>> Misfiring
>> choke has to be manually operated to get it started
>>
>>
>> INDICATED CAUSES
>>
>> IGNITION SYSTEM
>> IGNITION TIMING WRONG
>> unlikely-pertronix ignition
>> WRONG SPARK PLUG GAP
>> new plugs gapped to 0.020 autolite 216
>> WORN POINTS OR IMPROPER GAP SETTING
>> Pertonix
>> BAD IGNITION COIL
>> Coil was marginal. swapped out for a good one (no
>> change.)
>> FAULTY SPARK PLUG WIRES
>> wires tested good, swapped out for known good (no
>> change)
>>
>> FUEL SYSTEM
>> OUT OF FUEL
>> pump flow and pressure test good
>> LEAN FUEL MIXTURE
>> RICH FUEL MIXTURE OR CHOKE STUCK
>> choke not stuck
>> ENGINE FLOODED
>> POOR QUALITY FUEL
>> ran with external fuel tank with fresh fuel, no
>> change
>> DIRTY CARB
>> carb cleaned and rebuilt, (some question about
>> rebuild), however no change
>> DIRTY AIR FILTER
>> air filter removed, no change
>> DIRTY FUEL FILTER
>> new filter, no change
>> DEFECTIVE FUEL PUMP
>> pump flow and pressure test good
>>
>> INTERNAL ENGINE (when engine finally starts runs good until it
>> quits)
>> WRONG VALVE CLEARANCE
>> BROKEN VALVE SPRING
>> VALVE OR VALVE SEAL LEAKING
>>
>> COOLING SYSTEM
>> POOR AIR CIRCULATION
>> cooling air flow not blocked
>> runs same rolled in or out of drawer
>> DIRTY OR OILY COOLING FINS
>> with cylinder head covers off fins are observed to
>> be clean
>> BLOWN HEAD GASKET
>> no noise or exhaust gasses in discharge cooling
>> air.
>>
>> THROTTLE AND GOVERNOR
>> engine has same problems with linkages disconnect and
>> controlling manually
>> LINKAGE OUT OF ADJUSTMENT
>> LINKAGE WORN OR DISCONNECTED
>> linkages checked OK for connection
>> GOVERNOR SPRING SENSITIVITY TOO GREAT
>> LINKAGE BINDING
>> linkage checked to be freely operating and
>> properly lubed
>>
>>
>>
>> I'll be going over this list with a highlighter seeing if I can make more
>> sense of where the problem is. I would like to have another set of eyes to
>> look at this. I could be having some type of blindness that prevents me
>> from seeing the problem
>>
>> SteveS (going nuts in Palmyra)
>>
>> P.S. the spouse is very unhappy right now. This problem has caused us to
>> miss Amana. The phrase "happy wife, happy life" is not in operation at this
>> time.
>> --
>> Steve Southworth
>> 1974 Glacier TZE064V100150 (for workin on)
>> 1975 Transmode TZE365V100394 (parts & spares)
>> Palmyra WI
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> --
> Gene Fisher -- 74-23,77PB/ore/ca
> “Give a man a fish; you have fed him for today --- give him a URL and
> -------
> http://bdub.net/gmcmotorhome.info/
> Alternator Protection Cable
> http://bdub.net/gmcmotorhome.info/APC.html
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Stevc
I recently had much the same problem. My Onan would start and run for a small time and then stall. I found that if I chocked it the ONAN would continue to run (but not well). First I thought it might be the oil level but it checked full. Then I used a jumper from 9 to 5 to bypass my control board and the low oil pressure switch. It would till run a short time and then cut out. If I chocked it , it would continue to run.

This told me that it was a fuel delivery problem. Either a poor working fuel pump, a clogged carb or a pinched fuel line.

I untwisted the bottom of the pump and let the fuel drain out. I removed the bowl from the carb and drained it. I couldn’t see any obvious dirt so I reinstalled the bottom of the pup and the bowl of the carb. The Onan then started and ran fine.
Must have had some sediment that I drained out.

Emery Stora
77 Kingsley
Frederick, CO
>> On Sun, Sep 23, 2018 at 6:02 AM Steve Southworth

>>
>>> I'm having an Onan problem that is driving me nuts. Nothing I have done
>>> has solved the problem, or even helped.
>>>
>>> I have taken the "engine trouble shooting guide" from the manual and
>>> listed out all the items mentioned that can cause my problems. Also listed
>>> are
>>> reason each item may not apply, or actions taken. Please take a look at
>>> it and see if anything stands out to you. If I can't get the damn thing
>>> running I'm hoping to borrow a known good carb to test install. If the
>>> problem is still there I will know for sure the problem is not the carb.
>>> Obviously if it runs OK then the problem is the carb. If the carb, the
>>> mystery is still there. However when the book says the problem could be too
>>> lean or too rich how do ya figger that out. Also which system is the
>>> problem, idle mix or power mix?
>>>
>>> Also a good friend has taught me a very useful phrase. JUST SHOOT ME!
>>>
>>>
>>> ONAN
>>>
>>> PROBLEMS
>>> Backfire at carb
>>> Engine stops after very short run (less than one minute)
>>> Governor hunting (suspect this is because of misfire or power loss)
>>> Misfiring
>>> choke has to be manually operated to get it started
>>>
>>>
>>> INDICATED CAUSES
>>>
>>> IGNITION SYSTEM
>>> IGNITION TIMING WRONG
>>> unlikely-pertronix ignition
>>> WRONG SPARK PLUG GAP
>>> new plugs gapped to 0.020 autolite 216
>>> WORN POINTS OR IMPROPER GAP SETTING
>>> Pertonix
>>> BAD IGNITION COIL
>>> Coil was marginal. swapped out for a good one (no
>>> change.)
>>> FAULTY SPARK PLUG WIRES
>>> wires tested good, swapped out for known good (no
>>> change)
>>>
>>> FUEL SYSTEM
>>> OUT OF FUEL
>>> pump flow and pressure test good
>>> LEAN FUEL MIXTURE
>>> RICH FUEL MIXTURE OR CHOKE STUCK
>>> choke not stuck
>>> ENGINE FLOODED
>>> POOR QUALITY FUEL
>>> ran with external fuel tank with fresh fuel, no
>>> change
>>> DIRTY CARB
>>> carb cleaned and rebuilt, (some question about
>>> rebuild), however no change
>>> DIRTY AIR FILTER
>>> air filter removed, no change
>>> DIRTY FUEL FILTER
>>> new filter, no change
>>> DEFECTIVE FUEL PUMP
>>> pump flow and pressure test good
>>>
>>> INTERNAL ENGINE (when engine finally starts runs good until it
>>> quits)
>>> WRONG VALVE CLEARANCE
>>> BROKEN VALVE SPRING
>>> VALVE OR VALVE SEAL LEAKING
>>>
>>> COOLING SYSTEM
>>> POOR AIR CIRCULATION
>>> cooling air flow not blocked
>>> runs same rolled in or out of drawer
>>> DIRTY OR OILY COOLING FINS
>>> with cylinder head covers off fins are observed to
>>> be clean
>>> BLOWN HEAD GASKET
>>> no noise or exhaust gasses in discharge cooling
>>> air.
>>>
>>> THROTTLE AND GOVERNOR
>>> engine has same problems with linkages disconnect and
>>> controlling manually
>>> LINKAGE OUT OF ADJUSTMENT
>>> LINKAGE WORN OR DISCONNECTED
>>> linkages checked OK for connection
>>> GOVERNOR SPRING SENSITIVITY TOO GREAT
>>> LINKAGE BINDING
>>> linkage checked to be freely operating and
>>> properly lubed
>>>
>>>
>>>
>>> I'll be going over this list with a highlighter seeing if I can make more
>>> sense of where the problem is. I would like to have another set of eyes to
>>> look at this. I could be having some type of blindness that prevents me
>>> from seeing the problem
>>>
>>> SteveS (going nuts in Palmyra)
>>>
>>> P.S. the spouse is very unhappy right now. This problem has caused us to
>>> miss Amana. The phrase "happy wife, happy life" is not in operation at this
>>> time.
>>> --
>>> Steve Southworth
>>> 1974 Glacier TZE064V100150 (for workin on)
>>> 1975 Transmode TZE365V100394 (parts & spares)
>>> Palmyra WI
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>> --
>> Gene Fisher -- 74-23,77PB/ore/ca
>> “Give a man a fish; you have fed him for today --- give him a URL and
>> -------
>> http://bdub.net/gmcmotorhome.info/
>> Alternator Protection Cable
>> http://bdub.net/gmcmotorhome.info/APC.html
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
I have seen one with similar problems; of course that doesn't mean it could even be close. But, anyway, it had had the fuel pump replaced with a supposedly low pressure pump, which it would have been for carbureted car engine but the generator used one that was in the 1 to 3 psi range so it was over riding the float and causing similar problems. I think it also had the carb main jet (the little screw/bolt that holds the float chamber on) clogged up and that only took three or four carburetor cleaning fluid soaks to get the thing working right. For several years since, it has worked just fine, almost the craziness length of time brought about by the problem solution.

jofarr, soddy tn, 26'er

----- Original Message -----
From: Steve Southworth
Reply-To:
To:
Sent: 9/23/2018 8:36:27 AM
Subject: [GMCnet] more Onan troubles, 6KW
________________________________________________________________________________

I'm having an Onan problem that is driving me nuts. Nothing I have done has solved the problem, or even helped.

I have taken the "engine trouble shooting guide" from the manual and listed out all the items mentioned that can cause my problems. Also listed are
reason each item may not apply, or actions taken. Please take a look at it and see if anything stands out to you. If I can't get the damn thing
running I'm hoping to borrow a known good carb to test install. If the problem is still there I will know for sure the problem is not the carb.
Obviously if it runs OK then the problem is the carb. If the carb, the mystery is still there. However when the book says the problem could be too
lean or too rich how do ya figger that out. Also which system is the problem, idle mix or power mix?

Also a good friend has taught me a very useful phrase. JUST SHOOT ME!

ONAN

PROBLEMS
Backfire at carb
Engine stops after very short run (less than one minute)
Governor hunting (suspect this is because of misfire or power loss)
Misfiring
choke has to be manually operated to get it started

INDICATED CAUSES

IGNITION SYSTEM
IGNITION TIMING WRONG
unlikely-pertronix ignition
WRONG SPARK PLUG GAP
new plugs gapped to 0.020 autolite 216
WORN POINTS OR IMPROPER GAP SETTING
Pertonix
BAD IGNITION COIL
Coil was marginal. swapped out for a good one (no change.)
FAULTY SPARK PLUG WIRES
wires tested good, swapped out for known good (no change)

FUEL SYSTEM
OUT OF FUEL
pump flow and pressure test good
LEAN FUEL MIXTURE
RICH FUEL MIXTURE OR CHOKE STUCK
choke not stuck
ENGINE FLOODED
POOR QUALITY FUEL
ran with external fuel tank with fresh fuel, no change
DIRTY CARB
carb cleaned and rebuilt, (some question about rebuild), however no change
DIRTY AIR FILTER
air filter removed, no change
DIRTY FUEL FILTER
new filter, no change
DEFECTIVE FUEL PUMP
pump flow and pressure test good

INTERNAL ENGINE (when engine finally starts runs good until it quits)
WRONG VALVE CLEARANCE
BROKEN VALVE SPRING
VALVE OR VALVE SEAL LEAKING

COOLING SYSTEM
POOR AIR CIRCULATION
cooling air flow not blocked
runs same rolled in or out of drawer
DIRTY OR OILY COOLING FINS
with cylinder head covers off fins are observed to be clean
BLOWN HEAD GASKET
no noise or exhaust gasses in discharge cooling air.

THROTTLE AND GOVERNOR
engine has same problems with linkages disconnect and controlling manually
LINKAGE OUT OF ADJUSTMENT
LINKAGE WORN OR DISCONNECTED
linkages checked OK for connection
GOVERNOR SPRING SENSITIVITY TOO GREAT
LINKAGE BINDING
linkage checked to be freely operating and properly lubed

I'll be going over this list with a highlighter seeing if I can make more sense of where the problem is. I would like to have another set of eyes to
look at this. I could be having some type of blindness that prevents me from seeing the problem

SteveS (going nuts in Palmyra)

P.S. the spouse is very unhappy right now. This problem has caused us to miss Amana. The phrase "happy wife, happy life" is not in operation at this
time.
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
You may want to try a different fuel source such as gas can to make sure you are getting enough fuel from the tank. I have run into several cars that
sediment in the tank would not allow enough fuel to stay running except short periods. I could blow back into the line and it would run a short while
then stop again, I used a gas tank to get one of the vehicles back until the tank could be cleaned. Just a suggestion.
--
77 Royale
455
Rear bath, SW Virginia
 
Hopefully this will get resolved today. RayE is bring over his working Onan carb. Probably more important is there will be a second set of eyes and
an additional brain working on this. The new brain probably being the most useful addition to the process.

I appreciate all the suggestions that have been made. After today an update will be posted.
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
 
> Hopefully this will get resolved today. RayE is bring over his working Onan carb. Probably more important is there will be a second set of eyes
> and an additional brain working on this. The new brain probably being the most useful addition to the process.
>
> I appreciate all the suggestions that have been made. After today an update will be posted.

After working on this all day yesterday the only thing that is reasonably sure is the problem is in the carb.

It may have something to do with the "nozzle". GMC manual and Onan manuals say nothing about the nozzle. The parts repair kit says not to touch it
or move it in any way. Also states that if it is disturbed it must be replaced with a new nozzle. New nozzles are NLS, no longer serviced.

Stay tuned while this rabbit hole is investigated. Some info has been found in various places on the net last night but the carb will have to be
inspected to see if these bits make sense. Not today however as I'm gonna play railroad today to give my brain a chance to recover from this carb
problem.
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
 
Steve, It may be a long shot, but I recall reading somewhere long ago that Walbro still rebuilds the Carbs.

It may be worth a shot to see if they can help or point you in the right direction

http://www.walbro.com/contact-us/
--
77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
Mid Michigan
 
I'll give them a call. I wonder if there is a modern carb that would do the job. I wonder if there is anyone still working at Walbro that was around
when the LMB-185 was being manufactured.

Maybe I should try to find a Walbro retirees contact
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
 
Steve,

I had a similar problem with my Onan a few years ago. It would run for an hour and a half, then quit. After cooling down, it would start up and run
normally, but this time for only an hour. Next time, only 45 minutes, then 30 minutes, etc.

I pulled the original fuel pump all apart and cleaned it, still the same behavior. I replaced the pump, with a Mr Gasket pump, and that took care of
the problem.

I have since replaced that Onan with a 'reconditioned' one and had problems with that one as well. I replaced the fuel pump on it as well, but still
had issues. I finally broke down and bought the 'exact replacement (Facet) pump from Jim K and that, at least, solved the fuel problem.
Unfortunately, it also had an intermittent problem with an aftermarket electronic ignition system that was a bear to diagnose. I installed a Grey
Bovee Pertronix system and it has been trouble free ever since.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member
 
Jim Kanomata at Applied GMC has replacement carbs for the Onan.

Emery Stora
77 Kingsley
Frederick, CO

>
> I'll give them a call. I wonder if there is a modern carb that would do the job. I wonder if there is anyone still working at Walbro that was around
> when the LMB-185 was being manufactured.
>
> Maybe I should try to find a Walbro retirees contact
> --
> Steve Southworth
> 1974 Glacier TZE064V100150 (for workin on)
> 1975 Transmode TZE365V100394 (parts & spares)
> Palmyra WI
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
First check the obvious. The fuel line under the slide out likes to take a memory and partly kink. This has fooled many "experts". There was a spring
on the hose from the factory to dress the hose but those rust away. Second, check that hose at the clamps. Hose can split there but he hidden by
clamp. Will suck air. Split can be almost invisible but air molecules can "see" it.
You may need a new O ring on the main needle. Easy 30 sec fix.
Assuming your float is set in range, set the idle mix and power mix screws like 2 turns out from lighly seating. Setting mixture has to be done in 2
steps. We run at 1800 so my belief is that the idle circuit is still contributing to fueling as opposed to in an Onan used in a garden tractor where
idle is idle and high speed is double our 1800.
Disconnect all AC load from unit
Get unit to run and warm up
Hold throttle closed against minimum speed screw
You may have to adjust screw to get a slow ldle stop point.
Adjust idle MIXTURE screw for best and fastest idle. Give a few seconds after each tweek to respond. When you find the center, you may have to
readjust minimum speed screw for less RPM.
Now slowly lean the idle mix screw just to where RPM wants to drop and back off to that edge.
Now release throttle and allow governor to take over.
Adjust main jet in similar way but go for center of range rather than the lean edge. This slight added fuel will he needed once load applied.
Close throttle and release to check response. You may have to slightly adjust the main jet for good response. If this is set to be stable then hunting
is minimized.
Meter ACV and set speed for 126VAC with governor spring in center default hole.
Apply load and do any very fine main jet adjustment if needed.
This is what I do and mine starts instantly.
On next cold start cycle final choke tweek can be done.

--
John Lebetski
Woodstock, IL
77 Eleganza II
 
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