Board index Flathead Power-Technical Questions, Answers, and Suggestions Knuckles OIL PUMP GOVERNOR


Post Tue Feb 15, 2011 2:23 am

Posts: 7
I'm new here so this may be an old topic. I'm rebuilding my 41 and when I install the governor and tighten it down,It binds the oil pump.I am turning the pump inside the gear case with my fingers.I have bolted the pump on by itself with the separator plate and used washers as spacers instead of the governor cover and it turns freely.I have bolted the separator plate to the governor body off the engine at thats when it binds.I have pulled the governor from the cover and checked for debris and everything looks good,The only cure I have come up with is to place extra gaskets in between the separator and the governor cover,I have 2 gaskets a .008 and one at.004 giving me a total of .020 and it turns freely.Is this normal or am I missing something. Prior to this the pump worked fine for 18 years and I had previously disposed of the gasket so I don't know the thickness or if it was doubled up.Any answers? Thanks Scrap

Post Wed Feb 16, 2011 1:53 pm

Posts: 152
Location: Carver, MN

So, if I understand your post correctly, the governor protrudes from the governor housing by an amount more than the gasket thickness. If you put the governor in the housing and lay a straight edge across it, you should be able to measure with feeler gauges to get a figure. Perhaps at some point in the past someone sanded down the housing to make up for a (thicker) home made gasket?

The governor's purpose is to lower the oil pressure at idle and low engine speeds. For what its worth, I am not really sure you need it. The '48-'57 service manual contains a service bulletin that outlines disabling the governor on '48 and later models. I have been doing this on Knuckles for 30 years and have never seen any problems associated with it. The only possible down side that I can envision is the possibility of the top end over oiling and not returning quick enough, and that only if the pinion bushing clearance was at the low end of tolerance and the rocker arm to shaft clearances were very loose, allowing the extra pressure to find its way to the heads.

There was a block off plate that took the place of the thin center plate, or you can just plug both feed and return holes in the governor housing (leave the governor valve out) and use your stock plate.

Maybe someone can propose a good reason not to do this.....

Post Thu Feb 17, 2011 12:33 pm

Posts: 7
Thanks for the info Lee, I've read about that modification,probably on one of these posts, but didn't know where the info originated or anybody who had done it,and discussed the results.I think I will pull the cover back off and inspect the cover and also use that feeler gauge idea,I hadn't thought about measuring it that way.Thanks again ,this gives me a couple of options.
Thanks Scrap

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