Sam Jones,

Thanks so much for the recap of Lieutenant “Roscoe”! I know a few Vietnam vets and I am a firm patriot too. Those communists with AKs still make me disgusted, wherever they are. Please continue the story in the March or April Thunder Press; I sure hope that his life turned out shiny and included many motorcycles. Thank you; I just had to write you back, it was that good. May God continue to bless America and our freedom, and our free roads and our choices for American-made vehicles. Thanks again, Sam.

Jeff Parks
Grandville, MI

PS—I was too young for Vietnam and my nerved-up mother, unfortunately, convinced me to go to college rather than serving my country.


Thanks for the comments. You just finished the story for me. His life does turn out shiny and includes many motorcycles.

Slippery Sam


Your article had a lot of good info. Some Vincents have the sit sumping problem, but they have a drain plug, too. The drain back is supposed to be prevented by the pump plunger fitting just right in the sleeve. The plunger is part number OP30 in the big picture. Conways has developed a check valve to deal with a sloppy plunger fit:

It seems to have a weak spring that is good enough to seat a ball while at rest, but gives way from the suction when the pump is working. Matchless singles had the same type of pump. Click here to see (scroll down ~40%)

Bruce Metcalf


I’m aware of several versions of this general idea. I own a Norton Commando, Triumph Trident, and have owned many other machines which… like the FXR… will let oil seep into the sump when parked for long periods. So, I have tried a great many so-called fixes for the problem! I believe none of the ball and spring designs are trustworthy. After all, a ball and spring built into the factory oil pump on FXRs (and all other Harley Big Twins from 1936 to the end of the Evo era) doesn’t work…so how is adding another going to?

The Conway unit…as well made as it is, remains another variation on a faulty theme. Put another way… “gravity always works”… defying it… not so much.




Seems to me that a/the kill switch wired with redundancy (to allay fear from wiring issues), so that the manual application on the feed valve would not only allow the flow of oil but ‘lectricity too! One assumes that you’d not shut the valve in question for short duration so I am curious about what timeframe, in terms of how long you’d anticipate not runnin’ the bike, you’d be thinking of. A day, week(s), month(s)?

Ciao, Pj


As my ol‘ buddy Moose used to say…”The most amazing thing about electricity is that it works at all!” I’m a subscriber–so most likely will stick (no pun intended) with a manual shutoff… ignition key tied to the valve lever, whether for weeks or months, if weeks or months it turns out to be. But I will think your notion over more thoroughly all the same.



  1. I’ve owned my 92 FXRS-SP since new and use a large mayonnaise puke jar which attaches to a fitting from the bottom air filter hose which is spliced. I attended an HD seminar, recut the ball seat, replaced both spring and ball and nothing works so I came up with this. Has worked for 113,000 miles!


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