Sumping Blues

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Sumping Blues


Post by King » Wed Jun 20, 2007 12:12 pm

Sumpin Blues

I was off on a job for two weeks and when I started my up 51FL I left a trail of oil for about a half mile. I measured the drop in the tank (1.75”) and it came out to about a quart that had sumped. I have the stock iron body pump so I suppose the first thing to check is the ball and spring to see if some crud may have built up around the seat lifting the ball. However I tried to remove the plug and it is bound up tighter than my big screwdriver (with vice grips assist) can budge.

So first off, any advice on removing the plug? And next, does anyone know who can repair the seat if that turns out to be the problem?



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Post by Fixman » Wed Jun 20, 2007 12:25 pm

King, our favorite mechanic at Madison Motorcycles in Ruckersville, VA has the tool to re-cut the oil pump seat.


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Post by King » Wed Jun 20, 2007 12:30 pm

Thanks Kent

I think it's time to pay a visit


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Post by Cotten » Wed Jun 20, 2007 2:59 pm


Have you tried a hand impact driver, like the cheap ones from Harbor freight?

Once you pull the plug and the spring you'll need a magnet to get the ball out. (Never re-use a magnetized ball!)

Cutters chatter. (And the round ones are stupid.)
Lapping just widens the seat, and leaves a mill profile that is larger than an oil molecule.
But both of these may be required as preliminarly steps if the seat has been damaged by someone beating upon it
Both require removal of the pump for cleaning.

The final step (often the only step) is to burnish the seat.
This can be done in minutes, in chassis, right through the oil.
And it occasionally gives a 100% seal (zero sumping even after a Chicago winter!)

You need a simple burnisher, as shown in the attachment.

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Post by 108 » Thu Jun 21, 2007 1:20 am

King, Had it done this before ? If it had been OK and then suddenly fills the crankcase it may have just been a bit of debris under the ball. I'd want to see it repeat before doing anything with the ball seat. Might be a broken spring too.



Post by VT » Thu Jun 21, 2007 3:00 am

yeah that burnishing tool is nice... but you can't buy one (or get there) from here. :lol:
I'd check the seat area for debris and check out that spring like 108 said. Got a camera? Show us where it broke..or...or...whatever it was that was in there.
Craftsman has 9/16 (blade width) drag link socket, #44511, with a fat blade to fit the wide gap on the plug.

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Post by Cotten » Thu Jun 21, 2007 12:55 pm

Anybody with a lathe and a propane torch can make a burnisher.
It's just a ball silversoldered to a piloted 5/16" bolt, fer cheeses sakes!

I commissioned a batch, but my subcontractor got out of control, so they are expensive. Please post me direct at for availability, because only a few are left.

(PS: They are still a lot cheaper than a shop would charge to just to pull your oilpump and replace it!)


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Sumpin Blues


Post by King » Thu Jun 21, 2007 3:29 pm

Well I rooted around in my tool box and found my old Brit impact tool and with a couple of decent whacks the plug freed (thanks Cotton). The spring looked OK and using a slightly magnetized rat tail file I got the ball out. Under x10 magnification you can see a bit of wear (scratches and tiny pits) on the surface of the ball so I suspect that is part of the problem. I cleaned the seat and didn’t find anything obvious but something might have been knocked loose and not detected. So we will see, but I think burnishing the seat will be a winter job.

After reassembly I took her out just after sunset. I don’t know what the magic ingredients were, just the right oxygen in the air, the perfect temperature, or maybe cause it was the Solstice Eve but she was in great song. She pulled like a freight train without a flat spot in any part of the range and we smoked the back roads for about an hour. It’s times like that when you know what riding our old iron is all about.!!

Thanks and good riding.




Post by VT » Thu Jun 21, 2007 3:37 pm

Check that witches hat (tappet screen) for debris. Hold it up to the light...there' more junk trapped in the screen than you can usually see.

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Post by Cotten » Fri Jun 22, 2007 2:04 am

Overhead oil screens are mighty scarce on '51s!

(And they are all downstream from the sump ball check anyway.)




Post by VT » Fri Jun 22, 2007 2:35 am

I thought it was a 58FL in a rigid frame. We'll if you have tappet screens.. then check them at every oil change, for the upstream side of trash :!:
Since I have your attention at the moment, imagine the market created if the last dots are connected to the kit build industry.
Tell me why this wouldn't work:
A jobber that already builds motors somewhere, enters into an agreement with V-Twin® where he buys Knuckle and Pan motors and 4 spd trannys from Tedd at a dealer, or better than dealer price. Tedd supplys the replacement parts (just like the factory did to their dealerships) of any parts the jobber needs to repair V-Twin motors or trannys. Open account, so the jobber sends parts back to V-Twin as he finds bad ones. V-Twin ships parts whenever the jobber needs them. Everything that ships, ships on V-Twin's UPS account #. Jobber sees nothing but parts and return paperwork (one piece of paper with an RGA number one it).
Jobber then sells the motors and transmissions to kit people (kit-niks) for an ** exorbitant amount of money.
The customer is now getting a "Motor Shop" ready motor and transmission, guaranteed. He just had to pay alot for it.
How many motors and trannys from Tedd do you think the jobber is going to need to pull apart (to whatever extent necessary), before the jobber realizes what is wrong with the motor or trans? Two or three of them? I bet the jobber can even figure out what he has to watch for, just by who the employees are, at V-Twin, that put it together. I have a photo of flywheels being torqued at V-Twins facility, so don't say they aren't manufacturers.
I watched Stett repair my V-Twin 4spd transmission. He's good. He diagnosed and repaired it for $250. Other people around the country are good. Other people can diagnose and repair these main components.
You can build a one-kit-bike per lifetime, EPA emissions exempt. What are we waiting for? People want a tapered sprocket shaft motor with an 8 ribbed cam cover - if you could sell them one than ran dependably.
Tell me what's wrong with this outline.

** Whats exorbitant?? If we were in the pits at NASCAR and the mechanics were talking about replacing Kyle Petty's camshaft and pistons, etc. (after every race), and they mentioned the cost, you wouldn't be complaining to them about how much you spent for and entire guaranteed replica Knuckle or Pan motor or tranny, they'd laugh at you.

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Post by Panacea » Fri Jun 22, 2007 4:42 am

How many young people want to spend big bucks for yesterdays' technology? Do they see the panhead as the most beutifull motor Harley ever built? Or as grandpas" bucket of bolts? I'm sure there are plenty of us fifty somethings around with disposable incomes to blow on a wrenchin' hobby, but the future of antique motorcycles as an American pastime ? Few "new people" are even capeable of changing there own oil much less keep a pan running. I hope I'm wrong....Mike



Post by VT » Fri Jun 22, 2007 7:01 am

You have a point there. Hard to imagine someone not being mesmerized by the look and sound of a rigid frame Pan or Knuckle. But, I suppose it's all being bred-out of existence so to speak.
You either accept World War 2 engineering for what it is or you don't.

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Post by john HD » Fri Jun 22, 2007 11:57 am

i would have to say i see plenty of 20 somethings at davenport every year so maybe there is hope.

i think the high cost of getting started in this hobby is a barrier to many.

most youngsters would probably opt to put a fart can muffler and a loud stereo in a honda, add some cool stickers and you are good to go...

all for less than the cost of a big twin engine.




Post by VT » Fri Jun 22, 2007 4:38 pm

Right on. :lol:

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