Gas/oil mix on mid '60's 9.9 hp Johnson

Lundman

Petty Officer 2nd Class
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Sep 25, 2006
Messages
142
What is the gas/oil mix ratio on a mid 1960's Johnson 9.9 HP outboard?
This is the motor that is on a used Sea Nymph 14 ft. fishing boat I am
getting ready to purchase. Can I use the newer TC-W3 oil in this motor
also? One last thing,...where can I get an owner manual for it if the seller
has no manaul for it and what about a service manual?
 

jbjennings

Captain
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Jul 18, 2007
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3,903
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

Just a note: there's no mid-60's 9.9hp. Mid 60's was a 9.5hp. It and the later 9.9's use 50:1 fuel-oil mix.
JBJ​
 

CATransplant

Admiral
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Feb 26, 2005
Messages
6,319
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

Let's get a model number on that outboard. You'll find it somewhere around the transom mount area. If it's a 9.5 or 9.9, it's 50:1. If it's an old 10 hp model, it's 24:1. Let's make sure what you have there before giving out numbers.

Both the 9.5 and 9.9 are lowboy engines, meaning part of the sloping cowling, at the rear, is below the level of the transom. The 10 hp is a classic-looking outboard with the entire cowling above the top of the transom.
 

jbjennings

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Re: Gas/oil mix on mid '60's 9.9 hp Johnson

Just a quick note while you're looking for the model number.....TCW-III is exactly what you want to use on any outboard from the 50's up that is 2-stroke in the smaller horsepower motors at least. How much of it is the question, and as Cattrans. said, can only be answered if you know exactly what you have. Basically, if the motor is stock and has the 2-line/3prong fuel line connector, it uses 24:1, if only the 1-line/2prong connector, then 50:1. IF you tell us what motor you have, we might be able to make some other suggestions that would be helpful as well, since this motor is new to you. BTW, iboats sells manuals if you're interested.
JBJ​
 

Lundman

Petty Officer 2nd Class
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Sep 25, 2006
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142
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

I am supposed to pick up boat/motor/trailer today. Once I find out the numbers on the motor,I will let you know either today or tomorrow for sure.
Then we can go from there. The owner says it's a 9.9 HP motor,but will find out for sure when I get the numbers. Maybe the motor's newer than what I think!
 

Lundman

Petty Officer 2nd Class
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Sep 25, 2006
Messages
142
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

I am supposed to pick up boat/motor/trailer today. Once I find out the numbers on the motor,I will let you know either today or tomorrow for sure.
Then we can go from there. The owner says it's a 9.9 HP motor,but will find out for sure when I get the numbers. Maybe the motor's newer than what I think!


Okay,...I have the numbers from the motor. Model no. is 9R-70A
Serial Number is J3229657. What model year motor do I have here?
It is a Johnson in case you forgot.
 

jbjennings

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Jul 18, 2007
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3,903
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

It's a 1970 model 9.5 horsepower outboard.
It has a front motor mount that's difficult to replace, known to go bad, and the part itself is NLA.
Take the cowl off and wiggle the powerhead. It should have a little play but shouldn't be sloppy back and forth unless the mount is bad.
It's also known to have a gasket in the midsection that can go bad and leak exhaust into the cowl which will make it run crappy and not idle at all unless you take the cowl off.
You will have a hard time finding someone to work on that motor at all, and if so, they won't be reasonable on the price. So if you don't know or want to work on them, you'd be better off not getting a 9.5hp johnson. It's not a bad motor (I've ran one before) but it's nearly 40years old and annoying for an amateur to work on.
Just some thoughts and opinions---take them for what they're worth.:)
It does use 50:1 fuel/oil mix.
JBJ
 

Lundman

Petty Officer 2nd Class
Joined
Sep 25, 2006
Messages
142
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

It's a 1970 model 9.5 horsepower outboard.
It has a front motor mount that's difficult to replace, known to go bad, and the part itself is NLA.
Take the cowl off and wiggle the powerhead. It should have a little play but shouldn't be sloppy back and forth unless the mount is bad.
It's also known to have a gasket in the midsection that can go bad and leak exhaust into the cowl which will make it run crappy and not idle at all unless you take the cowl off.
You will have a hard time finding someone to work on that motor at all, and if so, they won't be reasonable on the price. So if you don't know or want to work on them, you'd be better off not getting a 9.5hp johnson. It's not a bad motor (I've ran one before) but it's nearly 40years old and annoying for an amateur to work on.
Just some thoughts and opinions---take them for what they're worth.:)
It does use 50:1 fuel/oil mix.
JBJ

Thanks for sharing that info,JBJ. That 9.5 Johnson came with the used Sea Nymph boat I just got Tuesday of this week. I have'upgrading' in mind at a later time,but want to see how the motor will do first. The boat,according to
the capacity plate,is rated for 25 HP max. If I upgrade to a newer Johnson
motor,I have been thinking about a late 1980's to early 1990's model. I think
a 15 HP motor will do me just fine on lakes where you have anywhere from an "idle speed only" to a 10 mph speed limit. But then again,if the boat is
rated for a 25 Hp motor,why not just get the max.hp motor the boat will allow
and be done with it. Would the newer 15 and 25 HP motors be easier to work on for an amateur? As long as the motor is Johnson or Evinrude,that is all that
matters.
 

jbjennings

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3,903
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

I just did a lot of work on my '99 30hp johnson because I hit a submerged log and broke the tiller bracket and some other stuff. I found it not nearly as easy to work on as my '50's johnsons and evinrudes. But not too bad. The ignitions on those motors are more difficult to troubleshoot in my opinion but not that bad either. I think an 80's or 90's 15hp would be the ideal choice for what you describe.
However, if you want a motor that is easy to work on and reliable, the late 50's and 60's johnson 18hp motors shouldn't be overlooked. Just look for one that has good compression and looks like it has been taken care of. If you live up North or the midwest you'd be crazy to overlook one of these if it's in good shape. I am using a '57 johnson 18hp that I bought on ebay non-running and looking pretty rough and have run about 25 gallons of gas through it in the past 3 weeks with no problems and it cranks in one or two pulls. It had bad coils and a bad upper crank seal, and needed an impeller and lower unit seals---about 90 bucks in parts total. I know you could find an even better one where you live.
Working on the 50's johnson and evinrudes is a lot of fun to me and I am very biased toward them. :) I will warn you, 50's OMC motors are like stray dogs, if you ever take one home, others are soon to follow!;)
Since you already own the 9.5, I'd clean the carb and get spark and see how it ran. If your mounts and exhaust gaskets are good, that's a good motor and not hard to work on as far as the carb., impeller, ignition, and lower unit. You just don't want to work on that exhaust gasket and motor mounts. Some folks really like those 9.5's.
By the way, if you don't mind me asking, why do all of your lakes have a 10mph limit? Are they small and folks are trying to prevent erosion from wakes? I'd hate to have to go that slow all the time.
Good luck,
JBJ
 

Lundman

Petty Officer 2nd Class
Joined
Sep 25, 2006
Messages
142
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

Not all the lakes have the low speed limit,...just the ones I frequent up in northern Indiana where you have a series of lakes in one chain,...such as
the Barbee lake Chain in North Webster,In. All the lakes,...with the exception of Big Barbee,...have the 10 mph speed limit within that lake chain. Back to
the motors,...will it hurt to run the newer TC-W3 oil in my 9.5 Johnson? Man,
I am anxious to get that thing on the water and see how she will run. Yeah,
I'd love to get my hands on one of those late 50's/early 60's Johnson motors.
My only concern is where in the heck would you get parts for them? That is
why I am leaning towards the newest motor I can get my hands on,...hence
the late 80's/early 90's motors. I should probably join antique outboard motor club then,...might find one of those '50's motors.
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

There's no problem getting the most-needed parts for the 50s and 60s Johnsons and Evinrudes. Internal engine parts are tough, but those outboards are sturdy, and if they have good compression and good lower units when you get them, they'll probably run another 50 years.

You can replace the entire ignition system for under $100, if you do your own work. Carb kits are available either here or at your nearest dealer or even Napa auto parts stores. Props and the like are common, both new and used.

Lots of folks here have them and are happy to help you fix problems.

One of the best deals out there is an 18-20 hp Johnson or Evinrude from the 50s or 60s. They're durable, powerful for their size, easy to work on, affordable, and fairly easily found. One of those would be ideal for your boat, I think, if you decide to increase your power.
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: Gas/oil mix on mid '60's 9.9 hp Johnson

LUndman,
TCW-III offers BETTER protection for your 9.5hp than the oil they had back when that motor was new. Heck yes you can use it!:)
Get that sucker running! Here's a pic of my favorites--I ran 6 gallons through the one on the right last Sunday, needless to say, it's not in the living room anymore!;)
JBJ​
 

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