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Who loves and understands their Original Onan ?

MC
Matt Colie
Sat, Sep 19, 2020 12:55 AM

rgogan wrote on Fri, 18 September 2020 13:34

<snip>
  1. The most challenging problem was the Walbro LMB 185 carb.  Experienced more problems with erratic operation that did not improve with a carb
    rebuild kit.  Still suspecting it was a carb problem, I sprayed light oil on the carb and intake manifold gasket and had a sudden change in the
    RPMs.  Checked the intake manifold gasket and found it was not leaking.  Finally found that the shaft of the butterfly throttle had worn out the
    bushing in the housing.  I was lucky enough on Ebay to find an unused carb that had been sitting on an inventory shelf for 40yrs.  It was a  LMB 181
    and externally was identical to the original Onan carb. I purchased and installed it, and despite all my previous problems, I am in love with this
    generator again.  The operation is unbelievable smooth and power has been restored.  Hardly any RPM change when both roof A/Cs kick in. This is even
    with the electric water heater in operation. Does anyone rebuild or rebush the throttle shaft?
<snip> Bob Gogan

Bob,
I have never had an LMB wear to that point, but I have had other Walbros do it.  Re-bushing the throttle shaft is not all that tough. I have even done
it when the shaft was so worn that one has to use UHMW bushing so that they can be slid onto the still full size section and then close fit the
section that had to get returned to be round again.
These get to be a little trick for a genset as the friction makes the governor hunt more than it should.
Save that carburetor.
Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

rgogan wrote on Fri, 18 September 2020 13:34 > <snip> > > 3) The most challenging problem was the Walbro LMB 185 carb. Experienced more problems with erratic operation that did not improve with a carb > rebuild kit. Still suspecting it was a carb problem, I sprayed light oil on the carb and intake manifold gasket and had a sudden change in the > RPMs. Checked the intake manifold gasket and found it was not leaking. Finally found that the shaft of the butterfly throttle had worn out the > bushing in the housing. I was lucky enough on Ebay to find an unused carb that had been sitting on an inventory shelf for 40yrs. It was a LMB 181 > and externally was identical to the original Onan carb. I purchased and installed it, and despite all my previous problems, I am in love with this > generator again. The operation is unbelievable smooth and power has been restored. Hardly any RPM change when both roof A/Cs kick in. This is even > with the electric water heater in operation. Does anyone rebuild or rebush the throttle shaft? > <snip> > Bob Gogan Bob, I have never had an LMB wear to that point, but I have had other Walbros do it. Re-bushing the throttle shaft is not all that tough. I have even done it when the shaft was so worn that one has to use UHMW bushing so that they can be slid onto the still full size section and then close fit the section that had to get returned to be round again. These get to be a little trick for a genset as the friction makes the governor hunt more than it should. Save that carburetor. Matt -- Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms SE Michigan - Near DTW - Twixt A2 and Detroit
R
Richard
Sat, Sep 19, 2020 3:38 PM

rgogan wrote on Fri, 18 September 2020 10:34

If you would like to hear about the other 10 more common problems, let me know.
Bob Gogan

I would like to see your list, Bob.

Richard

'77 Birchaven TZE...777;
'76 Palm Beach with 18,477 verified miles;
‘76 Edgemonte

rgogan wrote on Fri, 18 September 2020 10:34 > If you would like to hear about the other 10 more common problems, let me know. > Bob Gogan I would like to see your list, Bob. Richard -- '77 Birchaven TZE...777; '76 Palm Beach with 18,477 verified miles; ‘76 Edgemonte
RH
Randy Hecht
Sat, Sep 19, 2020 4:43 PM

As I am finishing the water systems this month in my GMC project, the Onan 4K is next on the list. So any information will be helpful.

On Sep 19, 2020, at 11:39 AM, Richard via Gmclist gmclist@list.gmcnet.org wrote:

rgogan wrote on Fri, 18 September 2020 10:34

If you would like to hear about the other 10 more common problems, let me know.
Bob Gogan

I would like to see your list, Bob.

Richard

'77 Birchaven TZE...777;
'76 Palm Beach with 18,477 verified miles;
‘76 Edgemonte


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As I am finishing the water systems this month in my GMC project, the Onan 4K is next on the list. So any information will be helpful. > On Sep 19, 2020, at 11:39 AM, Richard via Gmclist <gmclist@list.gmcnet.org> wrote: > > rgogan wrote on Fri, 18 September 2020 10:34 >> If you would like to hear about the other 10 more common problems, let me know. >> Bob Gogan > > I would like to see your list, Bob. > > Richard > -- > '77 Birchaven TZE...777; > '76 Palm Beach with 18,477 verified miles; > ‘76 Edgemonte > > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
JR
John R. Lebetski
Sat, Sep 19, 2020 11:45 PM

Big fan here as it was a joint GM/Onan project.  Usually we have a pedestal power at camp. Most use is when pulling into a truck stop or rest area for
lunch.  Toaster, espresso machine, microwave,  roof air, frig on AC.  I have no primer and still have points.  Starts right up every time.

John Lebetski
Woodstock, IL
77 Eleganza II

Big fan here as it was a joint GM/Onan project. Usually we have a pedestal power at camp. Most use is when pulling into a truck stop or rest area for lunch. Toaster, espresso machine, microwave, roof air, frig on AC. I have no primer and still have points. Starts right up every time. -- John Lebetski Woodstock, IL 77 Eleganza II
JC
Jack Christensen
Sun, Sep 20, 2020 12:17 AM

Well, I'm not sure I "love" my Onan, but I've solved most of its problems.
I resoldered all the connections on the control board
I installed something like the Bovee ignition before he had it developed.  I wish I had waited.
I converted it to dual-fuel using Jerry Work's kit.

I only run it on propane.  My problem with gasoline is that the Onan serves as the first warning of vapor lock when I'm driving.  Shortly after the
Onan quits, my 455 does as well.  Not a problem when running on propane.  On propane, it starts promptly, doesn't smell as bad as gasoline, and the
oil never seems to darken.  No choke required since the propane comes in as a gas.

Well, I guess I do love it now.

Jack Christensen - K6ROW,
'76 Glenbrook/Clasco - "The Silver Bullet",
Sebastopol, CA

Well, I'm not sure I "love" my Onan, but I've solved most of its problems. I resoldered all the connections on the control board I installed something like the Bovee ignition before he had it developed. I wish I had waited. I converted it to dual-fuel using Jerry Work's kit. I only run it on propane. My problem with gasoline is that the Onan serves as the first warning of vapor lock when I'm driving. Shortly after the Onan quits, my 455 does as well. Not a problem when running on propane. On propane, it starts promptly, doesn't smell as bad as gasoline, and the oil never seems to darken. No choke required since the propane comes in as a gas. Well, I guess I do love it now. -- Jack Christensen - K6ROW, '76 Glenbrook/Clasco - "The Silver Bullet", Sebastopol, CA
SF
Samuel Ferguson
Tue, Sep 22, 2020 3:48 AM

i would appreciate more info. I too have a ONAN 6K. Currently having carb issues even after installing a rebuild kit in carb. Running sluggish, intake
sweating & cold. Purred like a kitten until I replaced the fuel line from fuel pump to carb on gen. Put kit in carb with no good results. Figured I
should start researching for a new carb...

Thanks,
Sam

Samuel Ferguson
Summer Hill, Illinois
(West Central Illinois)
1976 GMC Palm Beach

i would appreciate more info. I too have a ONAN 6K. Currently having carb issues even after installing a rebuild kit in carb. Running sluggish, intake sweating & cold. Purred like a kitten until I replaced the fuel line from fuel pump to carb on gen. Put kit in carb with no good results. Figured I should start researching for a new carb... Thanks, Sam -- Samuel Ferguson Summer Hill, Illinois (West Central Illinois) 1976 GMC Palm Beach
JH
James Hupy
Tue, Sep 22, 2020 3:57 AM

When you changed your fuel line and immediately had runnability problems,
why would you look at your Carburetor? Just wondering!
Jim Hupy
Salem, Oregon

On Mon, Sep 21, 2020, 8:48 PM Samuel Ferguson via Gmclist <
gmclist@list.gmcnet.org> wrote:

i would appreciate more info. I too have a ONAN 6K. Currently having carb
issues even after installing a rebuild kit in carb. Running sluggish, intake
sweating & cold. Purred like a kitten until I replaced the fuel line from
fuel pump to carb on gen. Put kit in carb with no good results. Figured I
should start researching for a new carb...

Thanks,
Sam

Samuel Ferguson
Summer Hill, Illinois
(West Central Illinois)
1976 GMC Palm Beach


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When you changed your fuel line and immediately had runnability problems, why would you look at your Carburetor? Just wondering! Jim Hupy Salem, Oregon On Mon, Sep 21, 2020, 8:48 PM Samuel Ferguson via Gmclist < gmclist@list.gmcnet.org> wrote: > i would appreciate more info. I too have a ONAN 6K. Currently having carb > issues even after installing a rebuild kit in carb. Running sluggish, intake > sweating & cold. Purred like a kitten until I replaced the fuel line from > fuel pump to carb on gen. Put kit in carb with no good results. Figured I > should start researching for a new carb... > > Thanks, > Sam > -- > Samuel Ferguson > Summer Hill, Illinois > (West Central Illinois) > 1976 GMC Palm Beach > > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org >
RJ
Robert J. Gogan
Wed, Jul 21, 2021 8:07 PM

More Onan problem solving steps:

1)I always thought that my Onan would shut down in hot weather from overheating but vapor locking the fuel line, fuel pump or carb.  However forum
members would talk about crossing the desert with both overhead A/C units running and no Onan shut down.
Ultimately found the the clear fuel line purchased as a replacement from Cinnabar had developed micro cracks.  When cold the vacuum on the fuel pump
would work to fill the carb.  When the engine compartment heated up, the clear ?vinyl ?plastic (certainly not silicone) fuel line cracks would open up
and air would be sucked into the fuel pump.  Now I use plain old black rubber fuel line and my generator never shuts down in the heat.

  1. My Onan carb would run great just after the load run jet needle was adjusted, but within a few days it was running poorly again.
    This was difficult to figure out, but I found the O-ring on the needle jet adjusting screw was worn out and despite sealing against fuel leakage, it
    was not protecting the needle from getting out of adjustment from the engine vibration.  New O-ring installed and the needle keeps its adjustment
    about 2.5 turns off the base.

  2. bridge rectifier blowing out.  This has not happened again since I was warned about shutting the gen set down before turning the load off.

  3. starter motor bracket breaking off.  If your generator bangs around making all kinds of noise on shut down, the generator bracket is about to fail
    since it is making the noise.  Put new rubber engine mounts in because the old ones have failed or lost their clearances.

More Onan problem solving steps: 1)I always thought that my Onan would shut down in hot weather from overheating but vapor locking the fuel line, fuel pump or carb. However forum members would talk about crossing the desert with both overhead A/C units running and no Onan shut down. Ultimately found the the clear fuel line purchased as a replacement from Cinnabar had developed micro cracks. When cold the vacuum on the fuel pump would work to fill the carb. When the engine compartment heated up, the clear ?vinyl ?plastic (certainly not silicone) fuel line cracks would open up and air would be sucked into the fuel pump. Now I use plain old black rubber fuel line and my generator never shuts down in the heat. 2) My Onan carb would run great just after the load run jet needle was adjusted, but within a few days it was running poorly again. This was difficult to figure out, but I found the O-ring on the needle jet adjusting screw was worn out and despite sealing against fuel leakage, it was not protecting the needle from getting out of adjustment from the engine vibration. New O-ring installed and the needle keeps its adjustment about 2.5 turns off the base. 3) bridge rectifier blowing out. This has not happened again since I was warned about shutting the gen set down before turning the load off. 4) starter motor bracket breaking off. If your generator bangs around making all kinds of noise on shut down, the generator bracket is about to fail since it is making the noise. Put new rubber engine mounts in because the old ones have failed or lost their clearances.
CS
Carl Stouffer
Thu, Jul 22, 2021 2:31 AM

I love my 6-K Power Drawer.  I wouldn't even think about replacing something that was specifically designed for our coaches with something that needs
to be adapted.  My original Onan had 1679 hours on a broken clock when I got the coach.  I replaced the clock, but really had no idea how many hours
were on it.  It always started right up and ran fine, but it was a little tired.  The only problem I ever had with ti was that the fuel pump would
overheat and stop working under extreme conditions.

I was fortunate enough to purchase a "reconditioned" Power Drawer that Steve Ferguson had obtained from Kerry Tandy several years back.  I installed
it, and after fixing a few workmanship issues from the 'reconditioning' it has given me good service, especially after retrofitting it with the Gary
Bovee Pertronix ignition kit and a new Facet fuel pump from Applied GMC.  The only issues I have had with it were the one time I had the circuit
breaker trip while running both AC units on a 117 degree day. and having the generator shut down (from an overheated fuel pump) in 104 degree heat.  I
fixed the latter problem by simply opening the generator door, giving the pump some fresh air.

Any other issues have been self inflicted (burned traces on the control board that could be fixed with some wire and solder patches}

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

I love my 6-K Power Drawer. I wouldn't even think about replacing something that was specifically designed for our coaches with something that needs to be adapted. My original Onan had 1679 hours on a broken clock when I got the coach. I replaced the clock, but really had no idea how many hours were on it. It always started right up and ran fine, but it was a little tired. The only problem I ever had with ti was that the fuel pump would overheat and stop working under extreme conditions. I was fortunate enough to purchase a "reconditioned" Power Drawer that Steve Ferguson had obtained from Kerry Tandy several years back. I installed it, and after fixing a few workmanship issues from the 'reconditioning' it has given me good service, especially after retrofitting it with the Gary Bovee Pertronix ignition kit and a new Facet fuel pump from Applied GMC. The only issues I have had with it were the one time I had the circuit breaker trip while running both AC units on a 117 degree day. and having the generator shut down (from an overheated fuel pump) in 104 degree heat. I fixed the latter problem by simply opening the generator door, giving the pump some fresh air. Any other issues have been self inflicted (burned traces on the control board that could be fixed with some wire and solder patches} -- 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
CS
Carl Stouffer
Thu, Jul 22, 2021 2:54 AM

PS to the last post on this subject:  I still have my old generator in my garage if anyone needs one.  I'll make someone a good deal on it (local pick
up only).

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

PS to the last post on this subject: I still have my old generator in my garage if anyone needs one. I'll make someone a good deal on it (local pick up only). -- 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