79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

One last thing guys. After putting muffs on last night and starting it, making sure I had a good pee stream, etc, I noticed on the back of the engine the two holes that I thought were exhaust holes. I had a ton of water coming out the left side, but little to none on the right side. Attached is a picture so you know what holes I'm talking about as I don't know specifically what they are called...

Do I have another problem or is that just from the muffs? Something else I need to check?

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Those holes are called relief ports and a fine spray out of both is normal. If the water level in the leg gets high, more water will come out. I'm surprised you get a lot from one and very little from the other, unless there's an internal baffle. I would guess very high water pressure at the muffs could cause what you're seeing, but I'm guessing. Maybe someone else has a better guess. Did you replace or make sure the water deflectors under the heads were OK or replaced and in the right places?

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Those holes are called relief ports and a fine spray out of both is normal. If the water level in the leg gets high, more water will come out. I'm surprised you get a lot from one and very little from the other, unless there's an internal baffle. I would guess very high water pressure at the muffs could cause what you're seeing, but I'm guessing. Maybe someone else has a better guess. Did you replace or make sure the water deflectors under the heads were OK or replaced and in the right places?

I replaced all water deflectors in the same places they were originally. The old ones came out easily, and the new ones, particularly on the bottom of both sides, were a little harder to put in. I imagine because they were round and new...but I had to put quite a bit of pressure on the bottom ones to get them in all the way.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

I replaced all water deflectors in the same places they were originally. The old ones came out easily, and the new ones, particularly on the bottom of both sides, were a little harder to put in. I imagine because they were round and new...but I had to put quite a bit of pressure on the bottom ones to get them in all the way.

I just put the muffs back on and didn't give it as much pressure, and it didn't do it this time so I imagine it was the water pressure. The family wants to go to the River today (I live in Pierre, SD right on the Missouri), so we're going to take it out. Wish me luck, and I'll post my experience later on today.

 

[HybridMX6]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Best of luck! Hope all goes well. Let us know.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

I wanted to run the boat a little bit before I posted anything. Seemed like everything was fine...started right up, kind of babied it for a while...then full throttle and it got back up to its fastest speed quickly, good pee presshure, so I'm thinking, no worries. Took the kids tubing, for a 1/2 hour or so, then took a college kid last ad was going to give him a ride!! Turned a sharp corner an gave it more throttle, and the engine quit. Was able to start it again and if I kept it at fast idle, it would run. But when I idled it back, it would quit right away. Finally was able to get it in gear and limp back to the beach...would not go more than 5mph...did a compression test on the beach right away. Still got good numbers 125/120 and 125/125. The engine was not hot. Waited a couple of hours on the beach. Started the engine again, and same thing...it wouldn't stay running. Had it fast idle and threw it in gear real quick and limped around to boat ramp.

Put it in the garage and now now sure what to do next. I went out later and noticed a thick/black oil discharge dripping out of propellor. I serviced the lower unit and changed the fluid last fall.

What do I do now?

 

[daselbee]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Aw crap. Gotta check your spark next. Get a 15 dollar spark tester at the auto parts store, adjust it for 7/16 inch, and test the spark. You have unburned fuel running out the leg.
The instructions are here on this site many places. Look in the Top Secret file.
Call if you want.

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Sounds like mechanical health is just fine. That's good.

Black oil deal is probably unburned fuel/oil ... wouldn't be too concerned about that, especially during double oil period and it wasn't hot.

I hope you're observing the breakin RPM limts ... for at least 10 hours no extended WOT operation. See owner's manual for more detail here.

Start as D suggested with spark check. May not be firing all around. Could be a variety of things (coils, powerpack, stator, etc.) Consult your shop manual for specific procedures and likely items to check. BTW, I can't recall if you found an initial failure cause ... that's very important if you don't want a repeat.

Let us know what you find.

 

[daselbee]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Hey Jim,
No break in required...he just fixed a leaking head gasket.

Re-torque of the heads, yes....

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Guess I can blame it on CRS ...

 

[daselbee]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Guess I can blame it on CRS ...

Post is too long to rememeber.....s##t.
Correct on the unburned oil dripping out?
Can't be carbs. He was running fine and then...bam, nothing.

More likely ignition.

 

[scrawnyronny]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

DB in SD, Great thread. Love the many questions and the answers from the Iboat wizzes. Its threads like this that help give us with less stones the courage to maybe, step up to the plate. BTW the Columbo reference....I'd call it a pretty swell compliment.