what is the mix on my motor?

Marioleonard

Seaman
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Apr 27, 2009
Messages
68
I have a 1961 75hp johnson. I need to know what the fuel oil mix is and what type a spark plugs I need fo it thanks.
 

tootallofwa

Petty Officer 2nd Class
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Feb 20, 2010
Messages
177
Re: what is the mix on my motor?

My 40 has a how to start decal on the cowling access cover w/fuel ratio. These old motors are usually 24:1
 

JimS123

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Re: what is the mix on my motor?

J4J plug, gap at 0.030". No longer made....Current replacement is J4C.

That was about the time they switched from 24:1 to
50:1. I'd use the higher oil mix if it were mine, or contact an OMC dealer for their recommendations.
 

Marioleonard

Seaman
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Apr 27, 2009
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Re: what is the mix on my motor?

I am not sure what to run I have the 24:1 in it now and it smokes alot. Which one is better for the j4c plugs?
 

Marioleonard

Seaman
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Apr 27, 2009
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Re: what is the mix on my motor?

what is the diffrence between a restor plug and regular ones?
 

reelnative

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Mar 28, 2010
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Re: what is the mix on my motor?

guys I think that 24 to 1 was for 40w motor oil if im not mistaken I know it sounds weard but back in the day they didnt have 2 cycle oil and they used double what we use now because they used reg motor oil, just a thought tho ill go do some surfin the net and see what info I come up with on when they changed over from 40 w motor oil to 2 cycle oil but I do think it was about that time
 

JB

Honorary Moderator Emeritus
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45,907
Re: what is the mix on my motor?

GOOD GRIEF!!

The maker says 24:1, using modern TC-W3 oil.

Why guess??
 

cougar1985

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Oct 7, 2005
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Re: what is the mix on my motor?

GOOD GRIEF!!

The maker says 24:1, using modern TC-W3 oil.

Why guess??
no guessing on my part JB,talked to the local dealer about my new to me 63 75hp starflite and he said to use 24:1.so 24:1 it is .
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: what is the mix on my motor?

Reelnative, I think your recollection is incorrect.

If it were me, I would ask Joe Reeves for his recommendation, and follow it. I think he will say 50::1.
 

cougar1985

Lieutenant Junior Grade
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Oct 7, 2005
Messages
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Re: what is the mix on my motor?

Reelnative, I think your recollection is incorrect.

If it were me, I would ask Joe Reeves for his recommendation, and follow it. I think he will say 50::1.
i would not reccomed anything but the builder specs even if i thought other wise just for the simple reason if by some stupid coincidence they had a motor problem after, you know who they will be calling a jerk?lol.
 

JimS123

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7,952
Re: what is the mix on my motor?

Its true that 30 weight non-detergent motor oil was the product of choice years ago. When OBM oil was invented it was a real improvement. But, its also true that engine bearings were greatly improved over the years. So, the change to 50:1 was not made strictly because of the oil.

Some guys say they use 50:1 in all their motors regardless of age. That's their business. The "experts" say stick with the original ratio.

While I agree that the old ones sure smoke a lot, in actuality they smoked a lot back then too. Personally, I'm not concerned unless the plugs are fouling.
 
D

DJ

Guest
Re: what is the mix on my motor?

GOOD GRIEF!!

The maker says 24:1, using modern TC-W3 oil.

Why guess??

AGREED! Todays oils will smoke a lot less, especially the good synthetic stuff.

HOWEVER, that engine still needs that extra mix (24:1) for various reasons.

As a sidebar, I've experimented using less than 24:1 on some pre-'64' engines. I didn't have any issues but all of those engines were low performance (under 10 HP) that I trolled with a lot.
 
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