Fairbanks Morse by Onan. Carb Question

EvilDr235

Registered
I have a one cylinder Fairbanks Morse engine made by Onan. It is model 1B-7. Any idea what carb was used on that engine. I can't find anything to ID it and I can't do a picture at this time. It is an updraft carb.
 

mmcdonald

Subscriber
If no other help and you can post some good pics of the carb I might possibly be able to help with identification or parts. In the back of my mind I want to think it used a Zenith 59 but not sure.
 

EvilDr235

Registered
It is a Zenith carb. The number on the small tag is S895? as close as I can tell. I have found a picture of one from an old auction that was held last year. The information did not tell the model number. It just said off from an Onan generator. It has random numbers stamped on the little round tag. Most are stamped to lightly to read. I have no way to do pictures today. It is a straight updraft carb.
 

AZ Gary

Subscriber
I have that same engine and it has a Zenith Carb, doesn't seem to have any number. I didn't have a air cleaner for it and it wouldn't run without restricting the air intake. I bought a small air cleaner unit from Auto Zone and it runs great.
 

EvilDr235

Registered
Yep, that's the carb all right. I need to remove and clean it and the fuel tank be running it again. I am keeping an eye out for a belt-driven generator to hook to this engine. If I can't get a rebuild kit or another carb, I will search my hoard for a carb I can adapt. I want to thank you all and this site for your help.
 

Ironman

Registered
I just purchased a 1B-7 a little over a week ago. It is missing the bottom half of the oil bath air cleaner. Would like to find and purchase either just the bottom half or an entire air cleaner assembly.

I haven't looked over the engine very well yet, as I had just unloaded it and my other purchases from my truck and took a few quick pictures before tucking it away in storage. Are the points for this engine under the flywheel? If so, I guess I'll have to remove the shroud and flywheel to clean them as I did take a few seconds to check for spark and there didn't appear to be any. Does anyone know of a source of points and/or condenser should I need to replace them?

Is the 1B-7 designation strictly used by Fairbanks Morse, or was that Onan's designation as well?

Thanks in advance for any help that you may be able to provide.
 

Attachments

AZ Gary

Subscriber
Yes, all the ignition parts are under the flywheel. So you have to take off the flywheel do whatever, put it back together and if it doesn't work do it over again. I know from experience because I did it several times before I got it cleaned enough and set right. Be sure that you tightened down the flywheel good when it finally runs. I didn't, the flywheel came loose and broke the crank, so now it is yard art. Mine didn't have an oil bath on it so can't help with that. Any other parts you may need I might have. I got a new condenser at AutoZone.
 

EvilDr235

Registered
If you go to YouTube and type in ( Antique Onan 101 Electric Plant) there is a video of this type of engine. The fellow doing this video works on old generators all the time and old engines as well. He probably is a member on Smokstak. It is part of the 805ROADKING gang/crew.
 

Ironman

Registered
Yes, all the ignition parts are under the flywheel. So you have to take off the flywheel do whatever, put it back together and if it doesn't work do it over again. I know from experience because I did it several times before I got it cleaned enough and set right. Be sure that you tightened down the flywheel good when it finally runs. I didn't, the flywheel came loose and broke the crank, so now it is yard art. Mine didn't have an oil bath on it so can't help with that. Any other parts you may need I might have. I got a new condenser at AutoZone.
Gary- I'll keep you in mind should I be in need of parts. You had mentioned previously that you purchased a small air cleaner assembly for your engine at Autozone. Would you happen to have a part number for that air filter assembly? If not, can you provide a photo of it?

My engine does not have a screen to cover the flywheel fins at the opening in the shroud, nor did the engine in the Youtube video that was mentioned by EvilDr235. Does anyone know if this engine would originally have had a screen to cover the fins? If so, I wouldn't mind having one for the sake of safety- as well as making it as close to factory original as possible.
 

AZ Gary

Subscriber
Here are some pictures of the air cleaner I got. I mounted it on the carb by a hose and drilled the bottom to put in a fitting for the crankcase breather.You are welcome to mine but the packaging and postage will cost more than getting one from Autozone. You must have something to control the air flow or it won't start. Before I got the air cleaner we tied a sock on the bottom of the carb.
 

Attachments

EvilDr235

Registered
I have only been able to find a few pictures of this type of engine and none showed the engine having a protective screen on the blower housing. Glad I saw the information about needing a air cleaner for the engine to run. I have several small air cleaners that came off of VW Rabbits that were made to filter the air going into the smog pump. I will need to see if I can use one of those.
 

gnucklehead

Subscriber
I've never seen a screen on the blower housing, and I don't see it in the parts manual that I have (1B series generators and 358ARS military model).

I got a new condenser at AutoZone.
Do you have a trade# or any details on that condenser, and does it have the threaded stud for the wire connection? From the notes file - The original condenser is Eisemann H26-982.. Onan part# 312A1, 312-0001, 0.2mfd/300VDC, NSN 5910-00-164-7518
 

Ironman

Registered
Do you have a trade# or any details on that condenser, and does it have the threaded stud for the wire connection? From the notes file - The original condenser is Eisemann H26-982.. Onan part# 312A1, 312-0001, 0.2mfd/300VDC, NSN 5910-00-164-7518[/QUOTE]

I wonder if a condenser from an International Harvester H1 or H4 magneto would fit properly. They have a threaded stud on them.
 

AZ Gary

Subscriber
Mine had a clamp mounted on it. The new one I got at Autozone, I had to adapt a clamp to hold it.

---------- Post added at 06:38:00 PM ---------- Previous post was at 06:35:03 PM ----------

My original one had a mounted clamp on it. The new one I made a holder for it.
 
Top