1979 Johnson 115 HP source of water in gearcase?

[rdenis]

Big family ski n'fish trip starting in two days, so I go to change the lower unit lube today and I suddenly felt like making a sandwich - peanut butter specifically. Hhmm, that's no good as I watch the smooth brown concoction flow into my catch bucket.

Motor has been sitting for almost two years so the water has been there for a while. I seem to remember seeing some water the last time I changed out the gearcase lube (3 years ago?) so time to start thinking straight.

I drained the fluid then flushed the gearcase with mineral spirits. Figured I'd leave the fill and drain plugs out overnight as well. Can't remember ever replacing the O-rings on the plugs so maybe that's a source. Nothing like a little vaccuum/pressure test to verify the integrity of the gearcase at rest. Looked aroungd the garage for some bits and pieces to pressure test the unit. I managed to scrounge up an old pressure/vac gauge, a plastic Mityvac hand pump, some 1/4" OD clear tubing a plastic Tee and pulled the lower unit lube fitting from my pump. Perfect, put everything together and....

Perfect - no leaks on either the fill plug or the drain plug (even with the old O-rings). Tested both pressure (10 PSI) and vac (10 in/HG) at both holes to make sure I was covering everything off. Damn...

So now what?? I've got a 5 day fishing/skiing trip starting in two days with the family - not enough time to tear apart the lower unit to inspect and replace seals, etc.

My plan for now is to stock up on some lube and change it out each day on this trip and then plan to tear it apart in the offseason.

Anyone have any other suggestions on "mitigating" potential damage i.e. a bandaid solution to get through this trip?

 

[jimdd810]

Re: 1979 Johnson 115 HP source of water in gearcase?

hello
Well first off when you pressure tested did you vacumn test as well. I routinley put vacuumn and pressure up to 15 psi. I als o shift the the gears and turn and tug and pull on the prop. I also let the guage stay there for awhile just to make sure it is not leaking. I you have a marine repair shop nearby bring the boat to them and let them test it. They should have the stevens pressure and vacauumn guages for this. Then you will have a peice of mind. I would also replace the water pump. Motor has been sitting for a good while/ Better safe then sorry.
Good luck

 

[jonesg]

Re: 1979 Johnson 115 HP source of water in gearcase?

"Can't remember ever replacing the O-rings on the plugs "

They're $1 each !

We'll take up a collection for ya.

 

[rdenis]

Re: 1979 Johnson 115 HP source of water in gearcase?

Yeah I pressure tested and vac tested in a static state - I'll try engaging the gears and tugging on the prop - good tip.

If those pass the test, would it be justified to suspect the impellor system is the primary candidate as the leak source?

If so, can I run the leak test with earmuffs to verify this as the source? Or should I just run the engine with earmuffs and then drain the fluid to look for water?

Last question - any time estimate to change out the impellor system if I can get the parts before my trip?

Thanks for the wisdom guys.

 

[jimdd810]

Re: 1979 Johnson 115 HP source of water in gearcase?

you dont have to run the motor to find out if the gearcase is leaking. Take it to a marine shop and youll no the problem in like 10 minutes. As for replacing the water pump you can change that in about an hour if your mechnicly inclined.

 

[rdenis]

Re: 1979 Johnson 115 HP source of water in gearcase?

Ahhh the heck with the marine shop, this isn't rocket science - gearcase isn't leaking based on my pressure and vac tests. Anyways, going with my first plan since it seems the most viable at the moment - knocking on wood, Murphy's Law and all that.