Drainage from small hole in lower unit

AZNboater

Recruit
Joined
Nov 15, 2022
Messages
1
I've inherited a 1992 Yamaha 25hp 2 stroke - C25ELRQ. This outboard has low compression (about 75 psi in each cylinder) and one thing I tried was putting Seafoam Deep Creep in the cylinders to loosen things up. I noticed that the liquid drains out a small hole in the front-upper area of the lower unit. From what I can tell, this hole is supposed to be there but not sure of its purpose or if all this liquid should be draining out of the hole. I've added a picture for reference. It's hard to make out but there is a small hole just above the bolt. You can see oil draining from that area.
Anyone know if this is normal? Maybe this is a sign of bad crank seal or other gasket?
 

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Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
49,876
welcome aboard.

not normal.

at 75psi, the motor needs to be taken apart

the seapage looks like gear oil coming out where water would drain. to your lower needs to come apart.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,086
Step #1 is to do a compression test with a QUALITY gauge.-----And I would drain the gearcase and pressure test the seals.-----That leakage is normal on many 2 strokes.
 
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