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Discussion Starter · #1 ·
Got a 94 Fatboy that is blowing some heavy smoke. Just removed the front cylinder and I can see oil at the bottom of the crankcase. I stood the bike straight up and took a screwdriver and used it like a dipstick stuck it into the crank and it looks like I have 2 + inches of oil in the crankcase. I took a look at the oil filter and it had some sludge in it so I am thinking I might have a clogged oil passage somewhere. Anyone have any idea of how much oil should be in the crankcase if any?

Thanks
 

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Not much.

Likely it has seeped past the check valve in the oil pump, especially if the bike has been sitting awhile.

To check on the blowing smoke I'd do a compression test and a cylinder leak down test.
 

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Discussion Starter · #3 ·
Looks like it was the oil pump. The crank had WAY to much oil in it. Something went through the engine and pump. Almost sheard the keys on the pump shaft. I had to hone the front cylinder and put some new ring in. Looking for some info on how to break in a new top end.

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I put a good oil gauge in the oil pressure sending unit hole and start it a few times and let it warm up a bit. Make sure it keeps steady pressure at first. (As it warms up the pressure will start to drop a bit.) I'll do this 3-4 times from a cold engine, but never run it at idle long enough to get REALLY hot.

Then ride it for the first 500 miles while not reving the motor quickly and being a bit gentle with it. Nothing over about 60 mph or so, no fast starts, no extreme maneuvers. Just be sensible with it.

After 500 miles I change the oil and filter. I'll put a plastic baggie over the end of a magnet, (such as the type you reach for parts that have fallen under the workbench,) and drag that around through the drained oil. If it comes out with some oily fuzz on the end but not a huge amount that's okay. I'll then do a compression check on both cylinders, and if that's good then the bike's good to go.
 

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Discussion Starter · #5 · (Edited)
Thanks. Not to be a PITA but the book says @ 2000 RPM the oil pressure should be 12 to 35 PSI. Thats a big spread if you ask me. I get about 20 and I have seen it go to 30 when started cold. May have always stayed at 30 while warmed up before this problem. What do you usually see. Have no tach so with me its PSI while hot or cold and idle or moving along.
 

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The thing about Evo's is that, as long as everything is working, they always have enough oil and it never has much pressure, compared to other bikes. If you're seeing between 10 and 40 on a cold start after a rebuild you're probably okay. That engine pushes a LOT of oil through the galleries, but it doesn't have a lot of pressure.

If the engine is idling along on a very hot day you'll likely see the oil pressure drop to almost nothing, like maybe just 1-3 psi. It can be startling if you don't know what to expect.
 

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I am so glad you had mentioned that before Eye or the first time I glanced down at a light at the gauge I would have had a heart attack.
 
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