I have this old Onan BF 4.0 generator that I cannot find parts for. I think I have it diagnose down to a faulty R1 resistor (original problem) and a faulty CR1 diode(damaged while diagnosing). If I new the spects for them I think could find replacments but I have not been able to come up with anything. Any ideas?

Any color stripes on the resistor? Generally, diodes are diodes in that vintage, and a pack of 5 @ $1.95 from Radio Shack should do it. However, the labelling of the diode as CR1 is odd - it could be a zener or a voltage regulator. Do you have pix of these components?

Here is a picture. The Diode should not be a problem. The resistor does not have any color stripes, just a numer. The "CR1" and "R1" are just the way they are listed in the Onan service manual.

Well I just called the local Onan dealer again and talked to someone (a female) that was actually interested in finding the part. She was able to look them up and order them. The part number on my resistor matched the number she had so I may get the correct part. The only problem is it may take from 3 to 30 days to get the part. I will let you know how it works out.
Still looking for a cheap used 6.5 to replace the 4.0.

That's good! Now hopefully, that'll solve the problems.

The parts came in on the 9th, and they were correct and Identical to the originals. Pretty good for a 30 year old generator.
I installed them and had it up and working in an hour $40.00 later. I now understand how the generator works and if needed I could have gotten it working without the parts. If anyone needs help with the one of the older Onan units let me know.

Neil.

I do not know where the R1 resistor is located on the onan bf b 4000k Genset is. Can anyone help me?

A lot of info here:

https://www.google.com/search?...XGPCYKHb8HAxIQsAQIIg

Wow, that was 8 years ago. After having no luck with three more used ONAN generators I gave up and bought a used Honda unit. Two years later I have had zero problems with it. I dont think the ONAN units ever worked a complete trip without needing repair of some kind.

Thanks for the info. I was hoping you were still on here. So is that darn resistor by the brushes? there is no resistor in the control box just the diode. And I am not even sure if it is good. I just bought this motor home a couple of months ago. So I have no history.

Sorry Rob1957 but I cant remember exactly where it was located, its been a while. It shouldnt be hard to find with the size and shape of it.
NT

No problem, if you hear of someone who might be able to help me please pass it on. Thanks again.