Merc 300 Restore New Issue

[timmeraw]

After taking the boat out for its maiden voyage yesterday I decided to check the gear lube(after it was like Molassis the first time I checked it and have replaced a couple of times since) ...and news is not good. It was pretty milky(more yellow than the chocolate milk color I have seen before) so now I suspect the seals are dried out after sitting so long.

I am supposed to go on vacation to Canada on Monday and am concerned that I will not be able to do the job of replacing the seals before then(not sure if I can even get the parts locally). Looking at the manual it looks like quite a complicated job to tear the lower unit apart.

Would I be crazy to use it daily a bit (changing the gear lube after) or am I risking trashing the lower unit by doing so? There was no real visible water running out btw.

Thanks,
Tim

 

[outboardnut]

Re: Merc 300 Restore New Issue

kind of a loaded question....it all depends on how much water you get in there...however I've ran many with not so good seals and just changed the oil each time I went out. Sythetics seems to hold up to the moisture better. Make sure you get it changed before a freeze!

 

[timmeraw]

Re: Merc 300 Restore New Issue

What is the best way to flush out all of the old molassis stuff and newer lube that is milky etc before that? Should I just keep running new 90 weight thru it? Should I take it for a lake run to heat it up under load before draining because running in the tank in gear just kicks out the water and I have not been able to find the right kind of muffs to use a hose(where might I be able to get something that feeds water up under the cav plate on this old motor btw?)

 

[coolguy147]

Re: Merc 300 Restore New Issue

just use a barrel the flush attachment does lub the water pump while the motor is running.

 

[coolguy147]

Re: Merc 300 Restore New Issue

ya u can just let the gear oil drain out nice and good then u can refill it no really need to flush unless the whole thing is water but your choice

 

[Yepblaze]

Re: Merc 300 Restore New Issue

I used to drain it the next day, so it could settle out.

I always found the non marine 80-90w to be best at separating as the marine oils seemed to have emulsifiers that kept the water in the oil.

 

[timmeraw]

Re: Merc 300 Restore New Issue

After all the trials and tribulations restoring this boat and motor, I thought I would share with you kind folks, some before and after pictures of the '66 Whaler and the motor( wish I had taken some of the rusty old Merc after sitting in the barn for the last 10+ years).

http://s688.photobucket.com/albums/vv241/tmeraw/Whaler/

Wish me luck as I leave on Monday for a much needed vacation in Canada for some fun boating and fishing. Fingers crossed that the motor will hang in there.
Thanks again for all of your assistance.

Tim

 

[coolguy147]

Re: Merc 300 Restore New Issue

your taking that boat to canada?

 

[timmeraw]

Re: Merc 300 Restore New Issue

your taking that boat to canada?

Why wouldn't I? I don't get your meaning. I'm going to one of the most beautiful lakes in the world( Google Mazinaw Lake in Ontario) where we had a cottage when I was a kid. Why wouldn't I want to take this cool little classic Whaler up there to have fun?

Confused.

 

[timmeraw]

Re: Merc 300 Restore New Issue

As a matter of fact I am going to get an updated picture of my two teenage boys as a duplicate to this classic Whaler ad with the same motor:

 

[corm]

Re: Merc 300 Restore New Issue

Hi,

Nice restoration! it is very cool and will be a lot of fun in Canada.
Thanks for the pictures. I love see the vintage toys.
A foot note on your LU.
The thick grease was Merc Special grease. It is like a 105 wt grease
and was run in all Merc lowerunits until jet prop exhaust lower units came to be.
At that time Merc switched to 90 wt LU oil. You can run the 90 wt in your LU with no problem. Your right, the milky situation is from a little water. I would check the oil at the end of each day to drain off any pooled water and top off the LU. If it turn real light I would replace it as it will have a lot of water in suspension. Refill it and use it. I have run engines like this for a long time until I have had the time or motivation to replace the seals or add speedy sleeves to
renew the seal surfaces if they were to rusty to hold pressure.
Enjoy your vacation!