Hi all. I have an old B&S 18hp gas engine with an 8kw generator. I converted it to propane using parts from a floor buffing machine. But I don't have the governor parts that were on the engine. So I need help. I am asking for some suggestions. I wanted to make an electronic governor using a servo. But I have not been able to find a schematic to use to build one. Any help would be appreciated.
Thank you
Pete

 

Welcome to the forums.

That's a tall order there. Most servos have a dead spot which could be an issue. I've been trying to think of what to use.

Maybe someone else will chime in with an idea. I hear Furd coming

 

Sorry, but I don't have a clue as to where to even start in designing a servo-actuated governor for this application. Most small generators use a vane in the windstream of the blades on the flywheel to work against a spring linked to the carburetor throttle to control the speed. It's a bit crude but it generally works well enough. I would suggest researching what kind of governor this engine had from the factory and simply replacing it.

 

I think sourcing the missing parts and replacing what was already designed for this engine would be much simpler, faster, and probably cheaper than trying to re-design it. You would need a servo of some sort, and a processor with a tachometer that can step the servo up or down and a way to mount it, electric for it, and a way to connect it all. Sure sounds like a lot of hassle when there is already a reliable ready-made governor out there that you can just put on and be done with it.

 

First, I love working with electronics. I was thinking of using a frequency comparator with the output driving a PWM for the servo. I would pick off of the output from the genset to get the 60Hz I would monitoring.
Two, this is an old engine built before 90. ( I got this back then for just about nothing ) and I'm not in a hurry for it to be running anytime soon. I'm not sure I could even get the parts. I runs off of a shaft coming out of the block under the carb. That's all that is left...
Thank you for your answers, and if I can find the parts for cheap, then I will do it that way. This whole thing is more of a "Can I do it?" well, partly so far..
Pete

 

Nothing wrong with tinkering, but it sounds like your governor is there and intact. Sounds like all that's missing is the linkage. If so, 30 minutes and 20 bucks would probably have it back like it's supposed to be.

 

Well it did have a different carb on it. So I'm not sure if it would be a direct fit. Where would I look to find the parts?

 

You'll need to start with the model number of the engine.