Gearcase pressure test 1986 Evinrude 90HP

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
I'm the original owner of this outboard. I noticed some blue green oil on skeg and snow below it this last winter, so figured it was either unspent fuel (my 2-stroke oil is tinted blue), or gearcase fluid (mine is tinted green). Very hard to tell difference, but if it was really gearcase fluid it would have to be a big leak, and would had to have oocured without the engine even running. Last thing I do when I winterize is change the gearcase fluid, and it always looks just like when its new. Last fall I also changed the water pump, and did not notice any fluid by shift rod or driveshaft.

So yesterday I drained and pressure tested it (I did not take off the lower unit). I figured if it failed test I'd just order the gearcase seal kit and do everything. I did remove the prop to get a visual of the bearing housing and seals. Per manual, I pressure tested to 3-6 PSI. I sprayed soapy water on seal and housing where it bolts in. No leaks. I increased pressure to 16 PSI. I spun the prop shaft and no leaks at seals, but in forward top left section of bearing housing I could see just a few small slowly forming bubbles. None on bolts, just the housing. I left it at 16 PSI for 30 min and it lost only 2 PSI. So I'm positive what I saw on skeg had to be unspent fuel/oil mix. I ordered the kit anyway and plan to do it in the fall, given this engine is now going into its 36th year of service.

Am I wrong to wait to fall? I figure it really didn't have a leak, and that would give me time to find or make the tools I need. Thanks, Jim
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,431
I would not hesitate to do the seal kit now.----Seals do wear out over time.----Replace pinion bearing while it is apart.----No real special tools required either.
 

WestPoint

Seaman
Joined
Apr 3, 2009
Messages
58
I would not hesitate to do the seal kit now.----Seals do wear out over time.----Replace pinion bearing while it is apart.----No real special tools required either.
Thanks for your advice. I take it that pinion bearings usually wear out quicker than other parts?

My only hesitation with doing this now is that we have a boat access camping trip coming up in 3 weeks and this is my best boat for kind of trip. My small fishing boat would mean many trips to the island for gear, people and dogs, and my larger boat would have water depth risks. This Evinrude is on my pontoon boat- shallow draft and holds a lot.
 
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