Yanmar 2gm20 no throttle or shutdown control

Dec 18, 2022
2
pearson 32 c-10 caloosa marina
I made the mistake of taking the fuel injector pump apart, I’ve learned quite a bit about the thing but i still can’t get it to idle correctly with no load. It wont die with the kill switch either. Engine revs up and down between 2k and 3k rpm. I just found that i do I actually have control of throttle if in gear. Any help would be appreciated. Ty
 
Nov 6, 2006
10,102
Hunter 34 Mandeville Louisiana
Welcome to the forum!
in the top bar of the "Home" page, go to "Owner Resources" Then click on "General Downloads" then go down about 6 lines to "3GMF Shop Manual". It covers the 2 GM 20 as well. The injection pump and Governor sections will help. It sounds like a sticking fuel rack.. but could be a bunch of other stuff too..
 
Oct 26, 2008
6,295
Catalina 320 Barnegat, NJ
I had my fuel injector pump out a few years ago (3GM30f) and you must be very careful with re-installation. There is a pin on the fuel rack that must be aligned to fit in the fork of the governor assembly. If you are misaligned, the engine won't shut off with the kill switch. There is a window on the gear case, I believe, where you can peer inside to verify the alignment. You have to remove a cover, which means that you'll need a gasket to replace the cover, if I'm not mistaken. It sounds like you will be loosening the pump in any case.
 
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Likes: Ward H
Oct 26, 2008
6,295
Catalina 320 Barnegat, NJ
BTW, what did you do with the timing shims? They also dictate the performance of the engine, but I think you would have different problems if you didn't get them back in correctly. When I took my pump out, it bothered me that the shims appeared crumpled. For a relatively small amount of money, I replaced with new, but I was very careful to make sure with calipers that I replaced exactly in kind. I've had no timing issues as a result.