Billy Shaffer Onan

Several questions about an older Onan generator. It is a K 3500 idlematic, power express. The only #s I have found so far on the engine are 0276L and directly beneath GS280 Is this an engine that Onan built? What I am trying to do is find a replacement carb to replace the Kei Hin 28DGC DG 06 that is on it. So far no luck on ebay. How old is this unit? Can I still get a carb kit for it? Any and all help from any and all is appreciated.
 
Just remembered. That is a Kubota engine about 20 years old GS280-2DG-A3-B4. I am trying to match up the numbers now.
 
I am not good with links. But here goes.
Go to Twinslan Onan manuels

It will take you to a Smokstak link. Enter that go to post #4. Click on that one. It will bring up a list of manuals.

Look for 981-0509. That will give you the service manual for the 3500. You can download it for free. We don't charge.

Most of the sites I have found for that engine. List the GS280 as obsolete. I am still looking and have a few request out. I have a
friend in Hong Kong that may have something.
 
Thank you so much. I will pursue this, I at times am all thumbs when searching for info and at times its easy. This one has been all thumbs. Any guess as to the age of this thing? It belongs to a friend who picked it up at a yard sale. They had no clue as to the age or when it was last used. Many of the older units that show up from time to time here were new in 1989 when hurricane Hugo visited us. Generators were sold by the thousands, used for a few days and left to set unused for years. Of course they would not work when needed at a later time. Its been the same with each bad storm since. I have an old Coleman/Briggs 4000 that dates to 95 as a replacement for one that was stolen from my garage. I try to start it every 4 to 6 months then drain and refill the tank with fresh gas and stabilizer. It will normally start on the third or fourth pull. It seems so easy to keep them running and real hard to get them going if neglected.
 
I started with Onan in 1980. They were not out yet. I recall seeing a sales stand around 1983.They didn't sell well so Onan dropped
them. Around storm season down here. We see a lot of sales.So many were returned after storms were over. Most sellers came out with a
no return policy.
 
And that,s as it should be, I really do not understand how people justify doing that. I have had one since 1989 here as a back up. Not wired in just run a cord to the refrigerator and freezer, radio and a light if needed. I can get by without it but choose not to. I am in the process of cleaning the carb again. This time in a little cheesy ultrasonic jewelry cleaner I ran across. It was free and if the carb cleaner ruins it so be it. I hope the bowl gasket does not leak when done, we will see.
Thanks for the help so far, I was able to find and down load the manual and that should be a great help now and later on. I will let you know what happens.
 
I do these small engines as a hobby to keep me busy and help a few of my friends. As part of that I had a Stihl back pack blower last year that I worked on for a friend. It was a little hard starting but once warmed up did just so so. I had the carb apart and tanked 3 times and could not get it to do better. He took it to a very good Stihl dealer shop. They told him they did an over night in an ultra sonic cleaner, new carb kit,tossed my new plug and air filter put in another set of new ones. Charged him around $130.00 and it runs as new. That one unit pointed out how well they can work. I just can't justify the cost at this point for a hobby but I am getting closer.
 
I put the carb back together today. Turned the fuel on and it started dripping gas after a few minutes. Gently taped the carb and it seemed to slow. I was able to get it to run. It did well and the longer it ran the better it did. In the end no leaks running smooth at low idle and high idle. It stumbles a little when it throttles up on power demand. It does not seem to matter if a light fan load or a 1500 watt heater. Just a little stumble and it starts pulling as it should. This unit gave me more trouble than any other small engine ever. I simply could not make it run. It had compression spark and fuel although I was hand feeding it fuel through the air horn. I checked the valve clearance, spark was good, crank key looked in line. I pulled the head to check the valve seats. I found nothing, put it back together and it started right up. I am happy it seems to be fixed and I know the carb was a mess, but what exactly was keeping it from starting is a mystery to me. Seems to need a little choke to restart even warm but does restart on a pull or two. Thanks again.
 
A little stumble is normal and it should recover quickly. Will get better if you let it run more. With a load.

Had a funny day today. Putting out liquid feed when a hose let go. My helper looked like a walking pancake. I don't think my laughing
helped any. He was just standing there dripping syrup. He is leaving the cab for me to clean up.The way things have been going we
needed a good laugh.
 

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