for sure your bike doesn't have a crank position sensor like on the new ones, but it does have points which do the same thing, and are adjustable, which is even better!

If you want to keep your bike 'restored' then I would consider NOT putting an S&S carb on it, and finding somebody who knows what they're talking about to help you out. It may not end up being a hot rod, but it should certainly be able to run better with a proper tune up. My buddy has a 79, which is essentially stock, and has zero runtime issues. He rides that thing daily without a hiccup. Of course when he does run into a problem...

 

When I do an oil change, it seems to me I start with 2.5 qts and check it to midway between the dipstick marks after warming up. I've heard the term "wet sumping" before but I'm not sure what it is.

 

+1 - I've changed my Crank Position Sensor (CKP) 4 times and never leaked a drop of oil. Bike just resting on the jiffy stand.

A bad crank sensor will typically have thrown some diagnostic codes though, usually P0373 or P0374.

 

Wet sumping is when oil leaks down out of the oil tank into the bottom (sump) of the motor. This is common (normal) on bikes with their oil stored in a tank above the motor instead of an oil pan like a car. Sumping happens when the bike sits for a while and oil slowly leaks out past the check valve and into the motor sump. This is THE REASON that your told to check your oil level when it's hot and not when the bike has been sitting (cold). You can easily have 1/2 a quart of oil in the sump if the bike has been sitting for a few days.

 

Sounds like you put in the proper amount of oil. I usually dump in the full 3 quarts ( a little more than the recommended 2.8) Do you warm up the engine before an oil change?

The crank position sensor sits maybe an inch below the centerline of the crankshaft... if you lost a quart (!) out of that hole when changing the sensor, then your crankcase must have been damn near full. Did the bike sit for a long time before you changed the sensor? Does it normally have a real hard time turning over when cold ...or hot?

...at the risk of hijacking;
With the engine off, there shouldn't be more than maybe an inch of oil in the bottom of the crankcase (sump) with just the bottom of the crankshaft submerged... that's at least an inch below the sensor. I don't know if there is a check valve in the oil return line, none is described or shown in the shop or parts manuals. If the checkvalve at the oil filter is not functioning, then it may be possible for your oil bag to drain into the case over a few days.

Wet sumping occurs during engine operation, when the scavenge portion of the oil pump cannot suck the oil out of the engine faster than the pressure side delivers. Eventually the oil level inside the sump rises and gives symptoms. The crankshaft is now thrashing an excessive amount of oil, this causes loss of power, overheating, poor oil drainage from the top end... your engine is literally drowning in its own lifeblood! One of the possible side effects is cooking your crank position sensor in overheated oil. Most wet sumping occurs when running for extended periods at high RPMs, and is not necessarily the result of a malfunctioning oil pump, but rather poor engineering. Drag racers struggle with this problem often. Buell seems to have found a working solution with their slightly redesigned oil pump, which is a bolt in replacement in the rubbermount XLs.

 

Yes, there's a check valve, it's part of the pump assembly.

 

I know what a check valve is from installing sump pumps in basements. It sounds like I may have one that's stuck/faulty. If it's part of the pump assembly, is a new pump required? I guess I got some readin' to do. I assume checking the level in the oil bag for a few successive days (or hours) after a short ride would indicate a bad check valve. Maybe checking the oil temp gauge on the dip stick, too. It's the OL's bike and she hasn't mentioned a loss of power. Probably not over-reved too often. It's an '04 with 45,000 miles. No problems until the cps issue. Sometimes it'll sit for weeks. It'd been sitting for a month or so when I swapped out the cps.

 

There is no check valve shown or listed for the oil pump in the parts manual, every other internal pump part is. The pump housing is not listed as a part number either. If there is a check valve in the housing, then yes, you would need to buy the entire pump. I don't believe there is a check valve other than the one specifically described at the filter housing, but that's only because I've never taken apart my oil pump, and have yet to see convincing evidence there is one. If there is one, H-D obviously feels it's not important enough to sell as a replacement part or document it for their mechanics. All I'm trying to say here is: make sure this is a real problem before dropping scratch on a new pump!


That would explain all the oil in the sump. If you would have fired it up for 10 minutes or so beforehand, the oil would have been returned to the places and levels it belongs, and the CKP sensor swap would not have caused a mess. I think in your case, sitting so long the oil drained back slowly through the running tolerances in the pump gerotors, and maybe the filter housing check valve. There is likely nothing wrong with the bike. This is also why it is important to warm up the bike before an oil change, or you risk overfilling the oil and blowing off the oil cap.

Do like you say, monitor the oil level in the bag over a week or two. If it drops noticeably, then maybe the pump tolerances are on the loose side, and you can replace it if you feel it is important.

The best solution is ride the bike more often

 

Thanks, Man.
I checked for codes before I put a fresh jet in the carb and nothing was there. I'll check 'em again out of curiosity, and keep an eye on the oil. Any additional thoughts or considerations are appreciated.
Ya learn something new every day.
Sorry for the hijack.

 

A partially failed sensor will not always throw a code. As long as it is sending some kind of signal the module will adjust timing accordingly. A bad signal is still a signal. Mine never gave a code, yet when I replaced it, the running problems disappeared. A riding buddy with an '06 was chasing gremlins for over a year before he changed out the CKP and solved all the issues, it never once presented a code. Don't count on codes to identify problems, it still takes detective work to fix these bikes.