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Original Post (Thread Starter)
#832818 10/25/2025 2:33 PM
by rcmatt
rcmatt
I have been off the board for some time spo I want to give uan update on my M3W using at least one quart of oil per ~200 miles. This suddenly happened after about 20,000 miles. One day it was fine, the next using oil and filling the "dry sump".

Bothe the leak down test and compression check were good.

With help from Larry at Morgan of New England I changed back to the S&S filter with a back flow valve with no effect. I then explored the reed valve. This was something I have not seen before in an engine (having worked on a lot of 4 cylinder Goldwing engines). So here is my understanding of what the reed valve does (correct me if I am wrong).

On the S&S the lower "dry" sump is seperate from the crankcase. When the pistons come down they create a positive pressure in the crankcase. This pressure opens the reed valve (a thin piece of spring steel) and allows the pressure, gases and some small oil spray to enter the sump. This pressure then vents up to the intake. The excess oil is returned to the system through a scavenger pump. When the pistons goes up it creates a negative pressure, the reed valve closes and the sump remains "neutral", .

However if the reed valve does not close properly, the negative pressure enters the sump and pulls oil into the sump which eventually is sucked into the intake. So, in effect" you have something similar to the oil injection system on an old two-stroke outboard.

Here is now the problem. It appears that that small strip of spring steel is actually made of UNOBTANIUM. Morgan does not have it. S&S responds with "X-wedge? We no nothing about no X-wedge."

I have tried flipping the piece over and it seems to help SOME.
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#836190 Jan 1st a 10:02 PM
by rcmatt
rcmatt
just an update, Indeed the $4 reed valve is made of unobtanium. However, I removed the reed valve, turned it over and now my oil consumption has improved, and the dry sump is not full overnight
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