pressure test lower end adapter

[film495]

I bought a little adapter with what I thought might be a 3/8-16 thread, which is what I think the drain plug is. I planned to just use a decent bicycle pump, and use the fitting to connect directly to an extention hose, and make a little adapter, to the standard I think 1/4" hose on any bicycle pump.

I thought a 3/8 male to 3/8 barbed adapter would work, but either I messed up figuring out the thread sizes, or screw threads don't match air hose adapter threads. or they sent me the wrong thing, but I think it is me.

So, is there an adapter I can just screw into the lower end, and just use a hose clamp to attach to a barbed end, and the hose just goes to a bicycle pump? I got a little hose extenstion that connects to a bicycle pump. I planned to just cut one end off, and attach the adapter with the barbed end, and then it would thread into the drain plug.

What I'm trying to do seems so simple, but getting the actual thread sizes is tricky and think I'm goofing i t up.

motor is a 1973 4hp Evinrude Yachtwin

 

[Scott Danforth]

Motor is 3/8-16

Bicycle stem threads are 5/16-24

Some air hose threads are 1/8" NPT

The adapter I use with my mityvac is the one from my $4 lube oil pump kit

 

[film495]

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will a 3/8" NTP male pipe adapter, fit the drain plug threads? this is what I ordered with a 3/8" barb on the other end, and it isn't even close. both ends are way too big, not sure if I'm lost on this, or they send me the wrong part.

 

[film495]

never used it on this motor, only a merc - but I had an old bottle of gear oil with the pump, and the plug fitting on it screws into this lower end fine.

it shouldn't be that hard to find a little brass fitting the same size, with a barbed end for a standard bicyle pump size barb 1/4" maybe. maybe I'll just quit trying and use the one from the gear oil pump.

 

[film495]

NPT is 3/8-18 I believe, so no go there. At this point I think I'll just buy another lower unit pump, for the fitting, and go from there.

 

[film495]

lower unit adapter

just went with a pump that comes with the metal fitting I was looking for. price for the fitting and a pump with several fittings the same, so - got another little pump with a metal fitting like I was looking for. will it work for pressure testing, we'll see. I'm not doing rocket science.

to find it, search for lower unit adapter

 

[Chris1956]

Gee, I pull the hose of the gear lube, screw it into the gearcase and stick a hand pump onto the hose.

 

[film495]

Gee, I pull the hose of the gear lube, screw it into the gearcase and stick a hand pump onto the hose.

this is my plan now. I started trying to find just the adapter, but had no idea what it was called, and never really used a hand pump, but one time. good I have you guys around to point me in the right direction, I was way off ... lol

 

[Chris1956]

The gearcase lube pumps work much better than squeezing the gear lube tubes.
The larger gearcases take 25oz of lube, so you often need an extra qt of lube as sometimes the pumps don't like to pump the last of the lube.