harleyKmodel

I am trying to build a kmodel oil pump out of a box of old oil pumps. will a sportster oil pump that feeds from the back work if I block the rear oil feed. Bill W

Tom's pump seal invention is the bee's knees and worth the wait-- I might buy one for my 1962, now that I don't ride it as much as when I was working.

Someone else here might have a correct pump body too. I suspect you can use the late model pump, since all the internal feed does is provide a simple drilled passage to the top of the pump. You should make sure the gasket for that pump will work, it would be a disaster if you starved feed from the engine. I think the aftermarket pumps brag they work on K models as well as Sportsters, but they are not clear if they can feed either way. Picture how the oil flows in feed and scavenge and you should be able to see any problems.

And you can see all the pumps on this very site on this page here. To me it looks like they did the rear hose-feed by drilling back out the boss where they had a pressure blow-off valve in the 1952-1956 pumps. So another question is what happens when you don't have a pressure relief valve on the K-model, if that is what you are building. Less of a worry if you are trying to build for an early Sportster.

Bill I have a large pump body collection. If you need an early K body just let me know it's yours. I will look at them to try and answer your question. Erik K

Tom, I looked in ebay under K model oil pump and K model and didn't find oil pump you mention. What is the number it's listed under or what is your ebay "handle". Thanks, Ron

I’m looking for an answer and I found this old thread. On my 1955KHK oil pump I am looking at part number 26389–55 and ball 8866, is there supposed to be a spring over the top of that well pump Bill setscrew? Specifically does the 55KHK need spring number 26374–52? In the parts manual it shows that’s for all key models but the 55KH models don’t show it. Also I look at the pictures in the tech area, the 55 does not seem to have a spring between the ball and the set screw. (If you would rather chat about it, PM me and I will provide my contact number.)

55panman wrote:Tom, I looked in ebay under K model oil pump and K model and didn't find oil pump you mention. What is the number it's listed under or what is your ebay "handle". Thanks, Ron

4045thomas Out camping call me Monday 4137834045

Mayday53 wrote:I’m looking for an answer and I found this old thread. On my 1955KHK oil pump I am looking at part number 26389–55 and ball 8866, is there supposed to be a spring over the top of that well pump Bill setscrew? Specifically does the 55KHK need spring number 26374–52? In the parts manual it shows that’s for all key models but the 55KH models don’t show it. Also I look at the pictures in the tech area, the 55 does not seem to have a spring between the ball and the set screw. (If you would rather chat about it, PM me and I will provide my contact number.)

Out camping call me Monday and I will see if I can help you out. Tom 4137834045

Thanks for the chat today Tom… Unfortunately I’m no closer to my answer. Can anyone tell me what the spring size/compression is on that? I am putting the bike in a show next weekend, and this damn question is keeping me from kicking her over for the first time since 1978.
Serious Calls ok at
(Five for won)-5won three-o o for too

I believe you can use the later style oil pump bodies with the rear inlet. It is blocked off by a set screw on those bikes that use the internal passage.
You can check this yourself (I did this a few years ago) just by confirming that the oil passage from the internal feed passage lines up with the internal passage on the oil pump that leads to the feed (bottom) side of the pump.
Be careful with the oil pump gaskets as there are different gaskets for different pumps.
There is no spring underneath the set screw for used to block off the rear entry hole. The only spring required is for the check ball in the front of the pump.