New 77 Johnson 115hp

DA505

Recruit
Joined
Aug 2, 2012
Messages
4
To me anyhow. Been browsing the forums for weeks. Only have a few dozen questions. Picked up this rig on a Aquarius invader. Been sitting for 8yrs and motor fired after 5 cranks. Motors been stored tilted up all this time. When I lowered it later I noticed oil leak out of prop a small pool. Drained lower unit and oil was dark black. Drained and refilled seems to have ever slightest leak. I barely feel lubrication on finger when running it along bottom of skeg but no noticeable drops at all. Could it have leaked upward being tilted all the way up then when lowered came out prop?? Purchased gear housing seal kit and seloc book. Book doesnt go step by step like I hoped. Also while running on muffs no noticeable water coming out exhaust holes. I read that 77yr models don't have much noticeable water spray and can get #1 cylinder hot. Seen conversion for tap in upper block for water to spray thru cowling. I'm a little apprehensive to drill thru block. Are the t-stats located under heads on bottom near cowling? Spent half a day freeing seized steering cable. Also purchased new impeller. Getting ready to tackle this monster. Any suggestions for this backyard wannabe mechanic? Sure like this old rig and can't wait to get it on the water.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: New 77 Johnson 115hp

The only service manual to work from is a genuine factory manual. Check out this website: outboardbooks.com. Black oil from the gearbox means it is old and has gotten hot. Possible it was low. If you got 26 ounces of black out of the gearbox, it may not be leaking. Put two new seals on the drain/vent plugs and run it-then recheck the oil level in the gearbox. On that year model, there is one thermostat called a vernatherm, located in the thermostat housing at the top of the midsection-rear of the engine. When you first start your engine, hold you hand back by the two exhaust relief ports at the top of the midsection. After running for 30-50 seconds, the thermostat will open. When it does, water droplets will form on your hand. That's normal.
 
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