Who loves and understands their Original Onan ?

[rgogan]

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.

 

[Carl Stouffer]

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

 

[Carl Stouffer]

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

 

[sgltrac]

The Barbarian however stinky is bulletproof and relatively easy to
troubleshoot if you have Duane Simmons Onan Info.

Sully
Bellevue wa

> 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
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

 

[boybach]

Well being the new guy on the Onan block, I thought I might as well chime in.

My generator had three main issues that I've fixed since I got the coach way way back in March this year :d
First up was the missing half of the choke mechanism. The genny ran if you manually choked it but I wanted it to work properly and JimK found me the
other half of the choke pull-off or pull-on or whatever it's called.

Fitted that part from Jim and it worked again from inside the coach but occasionally the mechanism stuck. Decided to take the choke assembly apart and
replace the insulation. I certainly know how the choke pull-off or pull-on works now!!

With that all tidied up, I re-routed some of the harness to what looked like a more logical placement and snugged up saggy old solder joints.

All tiddly, I was ready to call it "done" but alas, the starter decided to stick on from time to time, scary noises and something you REALLY don't
want.
Pulled the starter and solenoid and gave them a bloody good cleaning and lube. Fixed the problem, no more sticking starter and she ran predictably and
reliably for quite a while ..until it didn't. That day it ran rough with a strong gas smell. Turns out the gas smell was from gas dripping out of the
main adjustment jet. Re O-ringed it and the leak stopped.

It's been fine since.

Larry
--
Larry - Victoria BC -

1977 Palm Beach 40,000 miles, PO said everything working but forgot the word NOT. New Atwood fridge, water heater & furnace. New SS exhaust system,
6000w Onan, Iota Converter, R134A A/C, New fuel lines & heat exchange hoses

 

[Ken B]

My Onan has been very good. After decarbonizing the heads, setting the spark plug gaps correctly, installing Lawrence Gaskins Pertronix upgrade,
and setting the timing to a conservative 26 degrees BTDC it has run flawlessly.

I did have a vapor lock problem after mistakenly buying some E-10 fuel and running in 105 degree heat with the AC on. After I returned home I covered
the fuel pump and fuel line going to the pump with some foam backed aluminum tape for insulation. I only covered the line inside the cabinet. I have
never had another problem with vapor lock. This really was not an Onan problem. It was a 10% craponol diluted fuel problem.

I also did replace the 40 year old motor mounts and the starter bracket with a Ragusa Steel one.

The best upgrade was the Pertronix ignition which Gary Bovee now sells as a kit.

--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[rgogan]

Onan starter motor problems and fix:

Main culprit is oil dripping onto and clogging up the starter mechanism

If there is any oil dripping from the Onan, investigate the source and correct it.

My main problem was the oil filter mounting bracket loosening from vibration and dripping oil onto the starter motor.
New gasket and locktite fixed that problem from recurring after the starter was disassembled and cleaned.

Also had the oil pressure switch develop a leak not from the tapered pipe threads but from the housing itself.

 

[john r. lebetski]

All the small problems listed here are a culmination of
1) minor design weaknesses not forward tested for 48 years
2) age
3) bad past “mechanics”
4) neglect

Nothing major like rod knocks that are game delayers.
Actually I think #3 is the biggest issue. Once I undid everything the POs had done and put it back to stock, mine has always run when needed. No
primer. No electronic ignition yet. Never been de carboned yet

--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[Ken B]

I got thinking after I made the following posting.

Gary Bovee, with his kit, has made the installation of the Pertronix ignition so much easier than when I did it on mine and several other GMCs, that
now while would be a great time to do it on yours. I have done several on mine and other coaches and can do them in about 1 hour. So, so if you were
to tackle this I would allow 2 or 2.5 hours for a first timer.

This project would be a great one for anyone looking to improve their Onan operation or something to do during their lock down or semi lock down
status.

You will fix the mechanical points problem that was a poor design by Onan and make the timing rock solid in the process. You also can advance the
timing which makes the Onan run smoother and more efficiently (use a little less fuel). DO IT ONCE NOW and never worry about ignition problems or
timing changes again.

A second easy project is de-carbonizing the heads. Onan says to do it every 200 hours. Just do not over torque the heads when re-installing them.
DO IT and see how much smoother the engine runs.

I am passing the soap box on to someone else.

Ken B.



> My Onan has been very good. After decarbonizing the heads, setting the spark plug gaps correctly, installing Lawrence Gaskins Pertronix
> upgrade, and setting the timing to a conservative 26 degrees BTDC it has run flawlessly.
>
> I did have a vapor lock problem after mistakenly buying some E-10 fuel and running in 105 degree heat with the AC on. After I returned home I
> covered the fuel pump and fuel line going to the pump with some foam backed aluminum tape for insulation. I only covered the line inside the
> cabinet. I have never had another problem with vapor lock. This really was not an Onan problem. It was a 10% craponol diluted fuel problem.
>
> I also did replace the 40 year old motor mounts and the starter bracket with a Ragusa Steel one.
>
> The best upgrade was the Pertronix ignition which Gary Bovee now sells as a kit.

--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana