Bleed hole above reed block

[Buccaneer]

Working on a 1956 Mighty Mite, and replaces the top main busing
with one I had the of the correct OD, but had to bore out the ID.
After I installed the new bushing, I noticed a small bleed hole
in the reed block housing, above the reeds, that matches a hole
in the upper crankcase half. When probing the hole in the crankcase,
it dead ends into the new bushing. There was no hole in the old
bushing that matched up. There was a channel on the OD of the
bushing, that ran the length of the bushing, but from all indications,
it was turned 180 degrees opposite.
Not sure if the old bushing was installed wrong, or if I screwed up
marking it.

What’s the purpose of this little hole in the reed block? to the crankcase?
Does it re-burn excess fuel, help the reeds close, or what?

Thanks!

Prepare to be boarded!

[frankr]

Can’t say about the Neptune, but such a hole is commonly used to supply manifold vacuum to the upper bearing. The vacuum sucks crankcase fuel/oil up into the bearing.

[Buccaneer]

frankr wrote:

Can’t say about the Neptune, but such a hole is commonly used to supply manifold vacuum to the upper bearing. The vacuum sucks crankcase fuel/oil up into the bearing.

Frank, thanks for the interesting thought. If I drilled thru the bushing
thru the pilot hole in the crankcase, it would only be an 1/8″ up
from the bottom of the bushing, but perhaps that’s all that would
be needed to get oil into the bushing, which is close to 1-1/2″ long.
If the old bushing was installed wrong, or never drilled, that might explain
why it was “wore out”.

Prepare to be boarded!

[garry-in-michigan]

There is usually a slot above the bleed hole that goes the the top of the bushing to insure it is properly lubricated. . .

[Buccaneer]

garry-in-michigan wrote:

There is usually a slot above the bleed hole that goes the the top of the bushing to insure it is properly lubricated. . .

Garry, there was a groove machined in the outside of the bushing, that did
not go all the way to the top, and would have had no way to get oil to the inside
of the busing. Also the way the old bushing was installed, it was 180 degrees
turned from the bleed hole,
I stuck a drill bit in the crankcase bleed hole and drilled thru the bushing.
Can’t imagine it will do much, but maybe better than nothing.
Thanks.

Prepare to be boarded!

[frankr]

So if the bushing was 180, would the outside groove have aligned with the crankcase hole? Was it an Oilite busing? Oilite is porous like a sponge. Interesting.

Like I said, I don’t know about Neptunes.. At least not in this case.

[Buccaneer]

frankr wrote:

So if the bushing was 180, would the outside groove have aligned with the crankcase hole? Was it an Oilite busing? Oilite is porous like a sponge. Interesting.

Like I said, I don’t know about Neptunes.. At least not in this case.

Frank, if the old bushing was turned 180, the groove on the outside of the bushing would
have aligned with the hole from the reed box, but it would have just been
a passage into the crankcase, as the groove didn’t go to the top side
or into the bushing, hence I don’t see how it could have aided in
lubricating the bushing. I may have to buy another 1956 Mini Mite to
see how it’s put together, lol. The bushing was not oillite.

Prepare to be boarded!

[Author]

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