'72 Evinrude 65HP-- how to change oil in lower unit.

[mike64]

bought my boat & motor last spring from an old outboard mechanic (not an old mechanic, a guy who specializes in old outboards)-- he said he pressure tested the lower unit and replaced oil and seals. Said I should replace the oil and check for water in the oil 1/2 way through the boating season. Since I've only taken the boat out about a dozen times, haven't got around to it yet, but I'm thinking I should before this last month or two of boating season. Here's what I understand about the process from other posts, with questions:

I apparently need a torque screwdriver to unscrew the upper and lower screws. The lower comes out first, put down a pan to catch old oil, and unscrew the upper so the oil comes out. Right?

Is this where I do a 16-18 psi pressure test, withOUT oil? Does a pressure test need to be done every time the oil is changed, or just if there's water in the oil? where would I buy a pressure gauge-- auto parts store or marine supply, and about how much are they?

Adding oil-- I know for the hydroelectric drive I need the "type C" or premium blend oil. Does it come in a self-pumping type canister with attachment, like it appears to in the manual, or do I need to buy something for that?

The oil is pumped in from the bottom until it starts to come out the top opening, correct? Then replace the gaskets on the screws, reinstall top screw, then bottom screw and done...? I saw one post say they like to replace the screws too. Is this necessary or just the screw gaskets?

Do any other seals need routine replacing when changing oil, or only if the pressure test fails?

Finally, since I'll need to do this again when I winterize and I'll probably take the boat out only another 1/2 a dozen times or so, do you guys think I could get away with just doing it when I winterize, or is it a good idea to change the oil now?

Thanks, hope I didn't throw too many questions in there at once...

 

[david_r]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

let it set for a day or two without runnin it when you pull out the lower plug if water doesnt come out you probably dont have a leak.

you dont have to pressure check it every time you change it.

you put the oil in the bottom hole until it runs out the top so you dont get any air pockets.

you dont have to have a pump and all oils dont comr with one. you just have to squeeze the s*** out of the oil jug.

you do need to change the plastic washers when you change the oil to prevent leakage.

good luck and happy boating

 

[jay_merrill]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

I think David pretty well hit the procedure.

I'll add that you don't need to change the screw type plugs unless you have a reason to do so. The most likely reason would be if you stripped or partially stripped the screwdriver slot in the plug. If a slot is rounded off at all, I would replace a plug just because I would want to make sure that I could get it out the next time.

You've also reminded me that I'm about due to change the oil in my motor - thanks!

 

[mike64]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

Thanks, guys.

You've also reminded me that I'm about due to change the oil in my motor - thanks!

Glad to help! Hey anytime you need motor advice, jay...
Yeah, you poor southern boaters...got no handy reminders like "the imminent end of boating season" to know when to change oil, etc. I feel sorry for you

 

[HighTrim]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

I by no means want to discourage your from changing the oil now, but usually changing it before you winterize is the best time, to ensure that there is no water in there before it freezes. Nothing wrong with checking it mid season. The water will sit at the bottom of the gearcase, and will exit first if there at all. If there is water, then pressure test it. The water will make the oil look milky white in colour. I personally love the pumps, they are so cheap, and make the whole procedure that much easier. Not to mention cleaner. I hate trying to squeeze the oil out of those darn tubes! The following may help as well. good luck.



http://www.tohatsu.co.jp/en/boat/sales/sbs.html

I used the adaptor from the pump to make my pressure tester, along with some air line, and a bicycle air pump that has a built in gauge on it. Whole thing cost me about 10 bucks as opposed to the 100 they want online for the tester. The following is the procedure for testing, just for your records.

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.

here is a fairly cheap pre made alternative

http://www.thetoolwarehouse.net/shop/MIT-4050.html

 

[mike64]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

thanks HighTrim, good info! Especially on the do-it-yourself pressure tester. Can't believe they want so much for a pressure tester when I picked up an engine compression tester for $29-- I could have paid more, but the one I got seems like good quality.

 

[sailor bob]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

Thanks again to everyone who replied.

I have one of the pressure pumps that are used to fill the lower unit with oil. I wasn't sure this would pressurize enough. I'll use the fitting with my tire pump and incorporate a tee so I can use my old refrigeration gauges to measure the pressure. I'm looking forward to identifying the source of the leak and replacing the failed seal and sealing surface in lieu of replacing all the seals.

Cheers,
Bob

 

[samo_ott]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

Get a pump for the oil. It'll be the best $10 you ever spent in your outboard career!

 

[Gary H NC]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

Get a pump for the oil. It'll be the best $10 you ever spent in your outboard career!

Thats for sure! I gave 6 bucks for a pump at WallyWorld...

Another hint,use the biggest screwdriver you have that will fit the drain screws...

 

[72GlassMaster]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

Ok, I've got a clarification question, and I'll attach pictures for the benefit of others. The boat is a 72 glassmaster. The motor is a 65HP Evinrude, but I'm not sure if it's a 72 or not. I think it might be a newer motor (75?) since I think the boat came with a Johnson originally.

Most instructions say to drain the oil using the 2 screws, but my motor came with two flat headed screws (A & C) and a long allen screw in between (B). I removed all 3 ... and I hope I haven't messed anything up.

My questions are:

1. What's the middle allen screw (B) for? It can't use a washer because of its shape, does it need one?
2. My top screw (A) has a plastic washer, but my bottom screw (C) had no washer at all. I assume both need washers - where do I get them?
3. My bottom screw (C) has a magnetic stem. When I removed it there were some tiny metal shavings (not much, but some). I assume the magnet is doing its job by catching them, but my question is how much shaved metal is normal?
4. And finally, when I refill with new oil, should I be using the bottom hole (C) and refilling past the middle hole (B) until it comes out the top hole (A)?

Thanks in advance for your help.

 

[david_r]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

im not sure what the "b" screw is for.... i thought it was fro te screen.

a little bit of metal shavings is normal. its when you get a bunch or chunks coming out is when you need to worry.

you put the fluid in the bottom screw hole until it comes out the top screw hole. then put the top screw back in , then remove the pump and replace the bottom fill screw.

yes both should have had washers/gaskets.

you can get them here on this site. the oem # is 0311598

 

[Daviet]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

I beleave the "B" screw is to hold water screen in place. Just put it back in and don't mess with it next time.

 

[Neil74]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

I think the B screw is your bearing set screw, put it back in Other two are for gear oil change.

 

[F_R]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

I think the B screw is your bearing set screw, put it back in Other two are for gear oil change.

This is the correct answer. The B screw holds the pinion bearing in place. They put an allen screw in there so you wouldn't be confusing it with an oil screw and taking it out. You should clean the oil out of the threads and put a drop of Locktite screw lock on the screw threads to seal it. As long as you haven't run it with the screw out, the bearing shouldn't have moved and will be ok.

 

[72GlassMaster]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

This is the correct answer. The B screw holds the pinion bearing in place. They put an allen screw in there so you wouldn't be confusing it with an oil screw and taking it out. You should clean the oil out of the threads and put a drop of Locktite screw lock on the screw threads to seal it. As long as you haven't run it with the screw out, the bearing shouldn't have moved and will be ok.

And if I did run it with it out? ... I can't remember for sure, but I think I turned it over with the bearing screw out after squirting fogger down the spark plug holes. I assume that now I have to take the boat in to get it fixed? So much for the do-it-yourself-and-save-money approach.

Sigh.

Is there a way to check if I've screwed anything up? Preferably without running the motor since it's winterized now.

 

[mike64]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

It looks like you do have a newer model motor that uses a shift rod, not an electric shift. I'm not positive, because an electric shift motor is all I've owned, but I think the presence of a pinion bearing screw means it's a standard shift and not electric shift. I don't have that screw on my '72.

The '72 was the last model motor that was made with electric shift, and uses a thinner type of gearcase oil called "Premium" or "Type C". If you think your motor is a '72 but it's a newer model, and you put the "type c" oil in, make sure you drain and put the right oil in at the start of next season.

 

[F_R]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

And if I did run it with it out? ... I can't remember for sure, but I think I turned it over with the bearing screw out after squirting fogger down the spark plug holes. I assume that now I have to take the boat in to get it fixed? So much for the do-it-yourself-and-save-money approach.

Sigh.

Is there a way to check if I've screwed anything up? Preferably without running the motor since it's winterized now.

No way to check it without tearing it all apart. However, I seriously doubt that it moved just from turning it over to fog it. Now if you had run it across the lake.....

 

[72GlassMaster]

Re: '72 Evinrude 65HP-- how to change oil in lower unit.

No way to check it without tearing it all apart. However, I seriously doubt that it moved just from turning it over to fog it. Now if you had run it across the lake.....

Nope, no trip across the lake. I'm even 100% sure that I never put it in gear or adjusted anything other than the choke. I'll put the set screw back in and hope for the best. Thanks for the help.