Removal of water in lower unit???

[CHEF06]

Hey guys. I just did a gasket and seal replacement on my 82 rude 115 lower unit, because of a previous water leak. Replaced the oil and took it to the lake and came home to find more milky oil. It wasnt as milky as before but still a little. I was thinking that it could possibly be ressidual water left in the unit. My question is how can I make sure that there is no more water in the unit before I refill it again? How do you pressure check it also? Need a special tool? Thanks Mike

 

[tashasdaddy]

Re: Removal of water in lower unit???

Mike, did you replace the seals on the drain, and vent plugs, #1 place for water intrusion. i would drain it. fill it with kerosene, or diesel fuel, spin the prop a couple of times, by hand, let it sit. the drain. refill with oil.

just a side note. i had a cousin, who always flushed his 58 OLDS, engine with kerosene, when doing an oil change. he swears that why he got 350,000 miles out of the engine, before it was ever worked on, other than a tune up.

 

[CHEF06]

Re: Removal of water in lower unit???

Thanks for the reply. I have indeed replaced the washers on the drain plugs. How can I pressure test the unit? I have another question. When I first start up the motor I use a little choke to get it fired up, and it will fire right up, BUT when I go to lower the choke to drop it to idle it goes from revving real high to dropping down to a real low idle and sometimes it will stall.. It doesnt seem like there is a middle spot for the choke. Also when I had it on the lake I would put it in gear and there is alot of hesitation and it doesnt want to open up. Could not get it to go on plane. It was like the engine was pulsing. Does this sound like a gunky carb? Thanks

 

[tashasdaddy]

Re: Removal of water in lower unit???

the lever on the control is not the choke, it is connect to the throttle lever, and is the fast idle lever for starting. you push the key in to choke the engine. remove the cover, turn the switch to on, and push the key in, you will here a clik. it definately sound like dirty carb, miss adjusted idle, and link n sinc. get the carbs clean and afterwards do a decarb on the engine.

 

[HighTrim]

Re: Removal of water in lower unit???

Definately sounds like you need a carb rebuild.

Have you tried pumping the primer bulb to see if the fuel pump is failing first? Also, have you removed the core plug on top of the carbs, and cleaned the idle jets.

When you rebuild the carbs, remove the welch plugs and clean out the areas behind them.

That's the most probably reason for your problem, if it's in the carbs, which it almost certainly is.

A lot of folks try to skip that step when cleaning carburetors. It's almost always a mistake.

And like TD says, run seafoam in your fuel to decarb after.

 

[CHEF06]

Re: Removal of water in lower unit???

Thanks alot guys. That makes me feel alot better. O ya You are right about the choke...OOPS! I have the seloc maual and I have done just about everything else on this motor. This being said what is the probability I can do this repair myself. I've been told they can be a little tricky. Thanks again guys!

 

[wilde1j]

Re: Removal of water in lower unit???

To pressure/vacuum test a lower unit:
a) drain the gear oil
b) use an appropriate adapter with a gauge tee'd in to apply pressure or vacuum. No more than 15 psig for pressure. You can use a bicycle pump or any other compressed air source for pressure. For vacuum, you need a vacuum pump.
c) LU should retain some pressure or vacuum for 45 minutes minimum.
d) If pressure doesn't hold, submerge LU in water to find leak source [possibilities: drive shaft seal, prop shaft seal(s) (usually two), shift shaft seal and the fill/drain screw washers.]
e) replace offending seal(s) as required.

 

[HighTrim]

Re: Removal of water in lower unit???

Good post Jim, ty for the tip.

 

[aaron day]

Re: Removal of water in lower unit???

I have the same motor in an 83. I have had a small amount of 'chocolate milk' in the lower unit oil every time I change it. How big a deal is this? I have noticed it for the last 5-6 years, and thought it was no big deal. I planned to do nothing about it until I started reading this post.

When I change it, I would say it is the first ounce or less that comes out is milky.

 

[HighTrim]

Re: Removal of water in lower unit???

That is because the water sinks to the bottom, it is heavier than the oil. The next time you change the oil, make sure both seals are brand new, and use a quality oil. You may also want to flush it with kerosene or diesel fuel like TD stated. The seals are the number 1 place for water intrusion, so dont worry about it until you change these first. If still milky, you may want to perform the pressure test to see where it is leaking, gl

 

[CHEF06]

Re: Removal of water in lower unit???

Ok I have flushed the lower unit with diesel fuel and refilled with new oil. Made sure to tighten vent and drain nice and tight. I also have done a carb rebuild making sure to soak in carb cleaner then sprayed everything out with a can of carb cleaner. Then sprayed with compressed air. I am taking it to the lake tommorow and I am going to attempt a link and sync. Hope I can get it dialed in. I'll keep you posted.