Silliest Question on Fuel Mix - Thank you for your patience

[JDusza]

I recently acquired a 1958 Johnson 7.5 with the tank. The system looks good with the exception that the spark plug threads are completely stripped out. I am replacing the head.
The fuel mix instructions on the tank say 16:1 (8 oz SAE 30 weight to 128 oz gasoline).
Should I be using straight 30 or can I use a more modern two stroke oil?
What is the proper mix so I don't blow this engine? It is a great piece and I don't want to mess this up.
Than you,
J

 

[kbait]

24:1 with 2-stroke outboard oil will be fine. You will get many opinions. I personally run those outboards at 32:1 which is 4 ounces per gallon and have never had an issue. 24:1 to be on the safe side. Some folks say 50:1 is fine, I believe that’s a bit light on oil..

 

[JDusza]

Thank you.
Gonna go mix right now!
J

 

[jimmbo]

If it says 16:1. use 16:1 even with the TCW-3 Oils. That motor uses Friction Bearings, and needs Lots of Oil to Survive.

it will also help keep the Mosquitoes at bay

 

[Mc Tool]

Some of the older motors need extra oil to seal rings and oil seals and have bushes instead of rolling element bearings .
My old seagull runs 16:1 ( 1/2 a pint to the gallon ) . This was speced for 30w oil and the new stuff will lube the engine at 50:1 but it really needs that extra oil to aid sealing . TCW3 oils will run much cleaner than 30w , and as long as it doesnt foul the plug your good

 

[airshot]

Always follow mfgrs instructions for best life and operation!! When you start cutting corners....problems often arrise....

 

[airshot]

Many if today's synthetic two stroke oils darn near eliminate the smoke...I switched to some Quicksilver semi synthetic oil this season ( it was on sale)
and my smoke is really noticeably less, I gotta look close and almost no odor.

 

[tphoyt]

No odor would be a deal killer for me.

 

[Crosbyman]

I ran all min at 1L TCW3 per 25 L of 87 octane so 25/1 with no problems

you could trow in some Evinrude Carbon Guard additive to run cleaner

 

[saltchuckmatt]

Kbait's original suggestion will work fine. Never seen him give out any bad advice.

With today's oils, I'm running all my older 2 strokes with less than their original suggested oil ratios with 0 failures. This boat, with it's 1985 30 HP johnson, I've been running 75/1 for 3 years. Not necessarily suggesting it but I'm not having any issues. XD 50 is what I'm running.

 

[dingbat]

I switched to some Quicksilver semi synthetic oil this season ( it was on sale) and my smoke is really noticeably less, I gotta look close and almost no odor.

Ran QuickSilver Premium Plus for a number of years for the same reason.
Have since found Pennzoil Premium Plus to perform just as well for under $20 a gallon.

 

[jimmbo]

Kbait's original suggestion will work fine. Never seen him give out any bad advice.

With today's oils, I'm running all my older 2 strokes with less than their original suggested oil ratios with 0 failures. This boat, with it's 1985 30 HP johnson, I've been running 75/1 for 3 years. Not necessarily suggesting it but I'm not having any issues. XD 50 is what I'm running.

That engine has Anti-Friction Bearings throughout, the OP's Engine has Friction Bearing aka; Bushings. These need significantly More Oil, mainly to prevent Metal to Metal Contact, especially in the Connecting Rod Bearings. Leaner Mixtures, even when superior Oils are used, don't provide enough Cushion/Clearance

 

[racerone]

Agreed the wonderful , smooth running AD-12 model needs the extra oil.-----But once again this thread demonstrates the lack of knowledge of what really goes on once the fuel enters the airstream in the carburetor.----And what really goes on inside the crankcase.

 

[airshot]

Ran QuickSilver Premium Plus for a number of years for the same reason.
Have since found Pennzoil Premium Plus to perform just as well for under $20 a gallon.

Actually been using Pennzoil marine two stroke oil for about as long as I can remember. Mfgr says it can be used in both air and water cooled engines which I have done with O issues. BP had a coupon for the quicksilver stuff so I bought some. Looks exactly the same even though that may mean nothing, I did not get much smoke from the Pennzoil but there was some, however the synthetic blend stuff is almost no oil smoke. Depending on price/ sales etc I will go back to Pennzoil or buy more Quicksilver....

 

[dingbat]

Actually been using Pennzoil marine two stroke oil for about as long as I can remember. Mfgr says it can be used in both air and water cooled engines which I have done with O issues. BP had a coupon for the quicksilver stuff so I bought some. Looks exactly the same even though that may mean nothing, I did not get much smoke from the Pennzoil but there was some, however the synthetic blend stuff is almost no oil smoke. Depending on price/ sales etc I will go back to Pennzoil or buy more Quicksilver....

I think we're talking about 2 different oils.

Pennzoil Premium Outboard Oil and Multi-Purpose is listed as a multi-purpose 2 cycle oil

Pennzoil Marine Premium Plus is a Synthetic Blend specially designed for exceptional performance in marine applications.

 

[Chris1956]

Gee, oil threads are real fun. Johnnyrude put out a notice that motors before 1964 needed 24::1 oil mix, everything after needed 50::1 oil mix. And this was in the 60's.

Just saying.

 

[tphoyt]

Yea there will always be a lot of different opinions on this topic. For me when comes to bushings skimping on oil is just asking for problems.

 

[jimmbo]

Gee, oil threads are real fun. Johnnyrude put out a notice that motors before 1964 needed 24::1 oil mix, everything after needed 50::1 oil mix. And this was in the 60's.

Just saying.

The 1957 thru 1963 35hp and 40hp, as well as all the V4s 58-63, were fully Antifriction Bearing, and could tolerate a 50:1 provided a TCW Oil was used.

 

[airshot]

I think we're talking about 2 different oils.

Pennzoil Premium Outboard Oil and Multi-Purpose is listed as a multi-purpose 2 cycle oil

Pennzoil Marine Premium Plus is a Synthetic Blend specially designed for exceptional performance in marine applications.

My container says Pennzoil marine TCW-3 meets all mfgr requirements for tcw3 oils and suitable for use in air cooled two stroke engines. I have one container that states syn blend and another container that looks identical but no syn blend statement.....actually never paid that much attention. I can say the Pennzoil does create a little more smoke than the Quicksilver, but no other differences.

 

[saltchuckmatt]

That engine has Anti-Friction Bearings throughout, the OP's Engine has Friction Bearing aka; Bushings. These need significantly More Oil, mainly to prevent Metal to Metal Contact, especially in the Connecting Rod Bearings. Leaner Mixtures, eve

Agreed the wonderful , smooth running AD-12 model needs the extra oil.-----But once again this thread demonstrates the lack of knowledge of what really goes on once the fuel enters the airstream in the carburetor.----And what really goes on inside the crankcase.

n when superior Oils are used, don't provide enough Cushion/Clearance

And once again this thread also demonstrates that old school mechanics are set in their ways.

I know they have bushings...and I also know that 24 to 1 is lots of oil. Much much better oil. Again, I stand by my statement that kbait gives excellent advice and I'm sure he's done it. Of the negative feedback here, have any of you tried it? Or do you just like to pollute the earth for no reason.

I've mention here numerous times that I've leaned way back on my ratios with 0 failures and my outboards idles way better....I troll a lot so it's a factor.

I suggest you try it first before barking out on what you think it needs.

Cheers.