Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

[redgoat]

My owner's manual calls for SAE 20 or 20W motor oil for my 153 cu in mercruiser engine I/O. Owner's manual does say that SAE 30 is OK if the prevailing daytime temperature is above 90F. Most of my boating is done in the 70's and 80's. Is there any manufacturer still making this weight? Any suggestions on what I might safely substitute if this oil is no longer available?

 

[Bondo]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Any suggestions on what I might safely substitute if this oil is no longer available?

Ayuh,.... Go to Wallyworld, 'n buy whatever 10W-30 oil ya want...

None of it is gonna Hurt yer motor...

Just keep it changed once a year, 'n that ole 2.5l will run Forever...

 

[Lou C]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

If you are boating in the 70s or 80s, you don't want a 20W oil, it's too thin, you want either a straight 30, or 40, or use Merc's 25/40. Merc has spec'd straight 30 up to 50*, straight 40 above 50* or the 25/40 for all temps.

 

[Howard Sterndrive]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

OP must be looking at the power trim reservoir spec.... that's the only place Merc called for 20W in room temp ambients

 

[sherm1]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

I have struggled with a similar problem but after reading the viscosity info. found on seveeral websites I sorted it out and now use 10W40 in my mercruiser 5.7 2002 model. See the link below and it should help you with selecting an oil replacement. Happy Boating http://www.upmpg.com/tech_articles/motoroil_viscosity/
2002 Rinker 270 Just Passin Thru

 

[sschefer]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

10-40 Multi Vis is designed to cover a broader range of temps and will actually be better for your engine than single vis 20.

 

[fishrdan]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

OP must be looking at the power trim reservoir spec.... that's the only place Merc called for 20W in room temp ambients

^^^ That's what I'm thinking too. 20W it way too thin for that old of an engine, gotta be for the trim pump. My 1972 140HP (181ci) Mercruiser calls for either straight 30W for cold temps or straight 40W for warm temps. I'm running 20w50, though the Mercruiser recommended oil is their 25W40.

 

[achris]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

I use my boat in all weather from about 10C to 45C, and I am using 15W40 diesel engine oil...
I agree that 20 weight for the engine is way too thin for the temperatures he's operating in.

Did this just turn into an oil thread????

 

[86 century]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Give the op some respect for wanting to follow the oem spec.

my old 110merc2.5L ran just fine on 10w30 if that helps.

 

[Howard Sterndrive]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Give the op some respect for wanting to follow the oem spec.

my old 110merc2.5L ran just fine on 10w30 if that helps.

I have more respect for the factory service manual
and you and he are not reading the manual correctly, but yes it helps;
helps prove that the wrong oil doesn't always cause a problem

have a look at where 20W appears on this chart from the Mercruiser service manual, and then look at the thermometer on the left side for the temps that oil is used at
it's the perfect oil for an icebreaker

 

[redgoat]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Thanks to all who replied. Your comments and suggestions are appreciated. First I must mention the fact that I have owned this boat since new. I know this engine quite well as I do most of my own maintenance. The original owner's manual DOES in fact say specifically that 20 or 20w oil is recommended for the CRANKCASE. Trim oil is another area. Over the years I have been using straight 30 in my 4 cylinder engine and look how long it has lasted. However, it does seem to run somewhat hot perhaps because it is enclosed and gets little ventilation. I do run my bilge blower constantly now whenever I am underway--seems to help. I think I will take a responder's advice and try the Mercury/Quicksilver 25W-40 for my next boating season and see how it performs.

 

[LFR]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

hello, Mag 1 and accel (same source) makes straight SAE 20 / bought a case recently for my TILT TRIM, not for crankcase

 

[Don S]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

I can't say for sure that your particular 1967 owners manual specifically says to use 20W oil, but I do know that the OEM service manual for those years does not give that information.
I also have an owners manual from 71 that shows the same chart as the service manual. Again, it does not show using 20W oil at the temps you stated.
Here is a copy of that spec.

However, it does seem to run somewhat hot perhaps because it is enclosed and gets little ventilation.

Have you changed the impeller in the past couple of years?

 

[redgoat]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Here is the page from my 1967 Mercuiser Operation and Maintenance Guide for 120 & 160 stern drive engines. I hope the photo attachment is legible.

 

[Bondo]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Here is the page from my 1967 Mercuiser Operation and Maintenance Guide for 120 & 160 stern drive engines. I hope the photo attachment is legible.

Ayuh,... So how often do you go boatin' in 0? to 32? weather,..??

 

[Don S]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

It's readable, and also very old. Perhaps the spec was changed for a reason in my newer 71 version I posted earlier.

The other thing you have to consider is that oils change, and things get better. Mercruiser has upgraded their specs for ALL Mercruiser engines, not just the new ones.
Here is their new spec, scroll down near the bottom

http://www.mercurymarine.com/servic...nd-maintenance/faqs/mercruiser/?category=fuel

 

[redgoat]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Don,
Mercury recommends 20W-40 FULL Synthetic for ALL Mercruiser engines. That said, I guess that using their synthetic oil in an engine that has been using mineral oil for 40+ years is OK. . . or would you recommend that I stick with mineral oil and use the Mercury 25W-40.

 

[sschefer]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Don,
Mercury recommends 20W-40 FULL Synthetic for ALL Mercruiser engines. That said, I guess that using their synthetic oil in an engine that has been using mineral oil for 40+ years is OK. . . or would you recommend that I stick with mineral oil and use the Mercury 25W-40.

Run the 25-40 you'll be fine. They sell the same vis for 4 stroke outboards and inboards but they are clearly marked so pay attention to the label.

 

[Don S]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

Many times going from non synthetic to synthetic oil can cause the lifters to rattle. No problem with sticking to mineral oils. You can also stick with your 30W. You keep reading only the first line of the recommendations, not the full list.
Here is the chart that doesn't show up on the Merc site.

 

[fmalott]

Re: Cannot find SAE 20 or 20W motor oil for 44-year-old Sea Ray I/O

It's readable, and also very old. Perhaps the spec was changed for a reason in my newer 71 version I posted earlier.

The other thing you have to consider is that oils change, and things get better. Mercruiser has upgraded their specs for ALL Mercruiser engines, not just the new ones.
Here is their new spec, scroll down near the bottom

http://www.mercurymarine.com/servic...nd-maintenance/faqs/mercruiser/?category=fuel

sorry redgoat i'm not hyjacking i asked the same question a month ago and got great info but i'm reading all the post in your thread and no one has mentioned this quote from the Don S post
NOTE: We do not recommend non-detergent oils, multi-viscosity oils (other than as specified), non-FC-W-rated synthetic oils, low-quality oils, or oils that contain solid additives.