1970 650 4 cyl still making milk

[thejeep007]

hey new to the forum and iam rippin my hair out... i am new to the boating thing and made a few mistakes..... i am car mechanic so i fell iam mechanically inclined, so long story short stored the boat w/ engine up and water in the oil, froze cracked lower unit, put epoxy on the crack and held up for a beat run, at the same time i saw oil leaking from prop shaft area changed bearing carrier seals and prop shaft seals, after beat run water in oil again, good amount to. ran smoke test and ad smoke is coming from the 2 square holes under the engine cowling, any thought.... thanks everyone

 

[Chris1956]

Re: 1970 650 4 cyl still making milk

If you have changed the prop seals, and the repair on the crack is holding, then the driveshaft seal and waterpump base oring are the likely candidates for the current leakage. You will need to buy a new waterpump base with the installed seal. it will come with an impeller and the gaskets and orings.

BTW - the two square holes are for exhaust releaf when the motor is ideling in the water and the backpressure keeps the exhaust from exiting from the prop. What you saw was normal....

 

[JB]

Re: 1970 650 4 cyl still making milk

The most common cause of water in the gearcase is failed (used) gaskets under the vent and drain plugs. They a crushable, use once, gaskets.

Did you replace them?

 

[Moody Blue]

Re: 1970 650 4 cyl still making milk

Chased a similar problem a couple years ago. Changed the drain and vent gaskets, changed the complete water pump assy and seals and still had water getting in. Problem ended up being a bad shift shaft bushing seal. Bought a new assy and no more water.

There is a way of pressure testing the lower unit to identify the source of leak. Use the search feature on this forum to find details on the procedure.

Good luck.

 

[thejeep007]

Re: 1970 650 4 cyl still making milk

didnt change the gaskets and lookin while i am draining the oil out and NO GASKETS on plug jope thats the problem. i ran a smoke test w/ snap on smoke tester and had it coming out of what now i know is exhaust relief vents but how is my lower unit conected to the exhaust passage? are the crush washers copper type like on a brake hose mounting to a caliper? anyways goin out in the ocean tomorrow ill get gaskets on the plug and pray she dosnt let go out there, goin w/ other boats so no worries thanks for you help

 

[Chris1956]

Re: 1970 650 4 cyl still making milk

OK, it sounds like the waterpump base seals and gaskets or teh shift shaft bushing. I vote for the waterpump base seal andgasket.

After you remove the gearcase from the motor, you will see the connection to the exhaust relief

 

[thejeep007]

Re: 1970 650 4 cyl still making milk

changed the water pump beginning of last summer but if that what you think iam not one to argue. did everything not just the impeller, got a kit w/ lots of gaskets and key and housing

 

[Chris1956]

Re: 1970 650 4 cyl still making milk

If you changed it last year, the gaskets and orings are probably OK. That now points to the driveshaft seal in the base of the pump. pull the pump base and check the driveshaft for wear. Sand teh rust off of the driveshaft. Buy an new pump base and install using oil for lubrication.

 

[thejeep007]

Re: 1970 650 4 cyl still making milk

synthetic lower unit oil after out on the ocean for a day, mostly sitting w/ engine up..... salt water makes me nervous..