Fuel Mixture for 1960 Johnson ?

[jinx708]

Could someone confirm the proper fuel mixture for my model CD-17 ,1960 Johnson 5½ hp. motor? I have had mixed answers about this and have been running 50:1 and having to change the plugs often. It also smokes like crazy. I would greatly appreciate any input on this. Thanks, jinx

 

[ob]

Re: Fuel Mixture for 1960 Johnson ?

jinx708, Lot of mixed recommendations on mix ratios on pre 1960 motors since the development of higher quality oils. Since yours is a 1960 that even adds another twist.I'm guessing your original ratio recommendation was 32:1.I think whether you can run leaner is based on the type of rod and main bearings on motor.Needle bearing rods and mains can generally be run leaner with newer oils ,however I believe on bronze or babbit type journals it is recommended to run richer oil mix .One of the pros will pipe in and elaborate on specifics.

 

[jinx708]

Re: Fuel Mixture for 1960 Johnson ?

Thanks for the quick reply. If that was the recommended mix for 1960, would I use that for todays oils ?<br />---------------------<br />I found this master manual on CD ROM on ebay. It may help me with my questions and replacement of the water pump that has apparently gone out since last time I used it. Anyone had experience with using CD manuals in PDF format ?<br /> http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=26453&item=1873446433&rd=1

 

[MGuckin]

Re: Fuel Mixture for 1960 Johnson ?

Most outboards of that era were calibrated to use 25:1.<br />The oil today is of much better quality and it is a widely accepted practice to use 32:1.<br />As far as the smoking is concerned, might be a mechanical problem such as wrong plugs or carb set wrong, but all 2 strokes smoke.

 

[gsnyder]

Re: Fuel Mixture for 1960 Johnson ?

Jinx--Hello again. P.81 of the Johnson Service Manual says: "Our Engineering Department has, after long research and evaluation, developed a ratio of 1 part oil to 24 parts of gasoline by volume as best suited for the efficient lubrication of Johnson motors and economy of operation. The ratio of 1 to 24 is equivalent to 1/3 pint(5.33 oz.) to 1 gallon or 1 quart per each 6 gallons...We cannot stress too emphatically the value and importance of adhering to the engineered 1 to 24 ratio for continued uninterrupted performance...Care should be exercised during each refill to make certain the recommended 1 to 24 ratio spread is being constantly maintained at all times for best results." P. 82 Notes that starting with 1964 motors, Johnson's recommended oil and gasoline mixture is 1 part oil to 50 parts gasoline. The 24:1 mixture was based on SAE 30 Wt oil, not today's TCW-3 oils; nonetheless, I run 24:1 TCW-3 in both of my '56 motors with good results. See an earlier thread about the '57 Evinrude 7.5 and read the comments. I get quite a bit of white smoke, and goo in the water tank, but it's not a thick white cloud like you get from overfilling lawnmower engines. Double check what MG suggested..plugs should be Champion J6C or equivalent.

 

[Lark40]

Re: Fuel Mixture for 1960 Johnson ?

The 1964 change was not due to internal engine mechanicals. Rather, it was due to the newer oil technology. The roller bearings appeared years begore. We owned an Evinrude dealership from '58 to '69 and I worked on all these engines when they were new.<br /><br />This oil ratio for pre-1964 engines is like a religious topic - people have strong opinions and some don't want to accept that oil has improved.<br /><br />But, after 40+ years of experience, I use a good grade of outboard oil with a 40:1 ratio in my 1960 Lark. Could probably run fine with 50:1, but I like the extra margin of safety.

 

[jinx708]

Re: Fuel Mixture for 1960 Johnson ?

Thanks for the information on this. Seems to be mixed opinions but I took your advise 7.5 Runner and read the post on the '57 Evinrude 7.5. Sounds safe to use 24:1 or at least 5 oz. per gallon. Just sounds like alot of oil.<br /><br />----------------------------<br /> I used to have a '79 Johnson 115 on my old F/S Glastron. Now I have a '90 Mercury 150 on a 17' Tidecraft F/S.

 

[alcan]

Re: Fuel Mixture for 1960 Johnson ?

Hi Jinx<br /> I agree with 7.5runner. 24-25:1 ratio. If your smokin too much at 50:1 your running way too rich an air/fuel mix. Your motor sould run the recomended 24:1 all day for months and never foul a plug. Sounds like you might need a general tuning up. Yer going to have a little more smoke than with a later model. The only time you should really notice it though is when trolling on none windy days.

 

[JB]

Re: Fuel Mixture for 1960 Johnson ?

There are very good arguments on both sides of this (and in the middle, too).<br /><br />In the days that 24:1 was the standard (My old books agree with 7.5's) non-detergent motor oil was commonly used. It had no outboard-specific additives. It made lots of smoke and made carbon quickly.<br /><br />When TCW oil became widely available it included outboard-specific additives to reduce carbonization and smoke, but I don't think it offered superior lubrication.<br /><br />Later, TCW-2 and then TCW-3 improved lubrication at 2 stroke cylinder temps.<br /><br />Modern manuals recommend 50:1 using TCW-3.<br /><br />I have read many testimonials for using 50:1 with TCW-3 in even the old (pre-'64) engines, and do not recall a case of engine damage in a water-cooled engine. <br /><br />My little air cooled chainsaw and weedeater will overheat and sieze using TCW-3 unless I mix it at 16:1. On chainsaw oil, they both run fine on 24:1.<br /><br />The only 2 stroke outboard I have right now is a 1948 Sea King 1.5. She gets 24:1 with TCW-3.<br /><br />To be completely safe, use what was recommended when the engine was built, but too many people successfully use 50:1 to say it is dangerous.<br /><br />Good luck.

 

[DJ]

Re: Fuel Mixture for 1960 Johnson ?

jinx708,<br /><br />You've seen a lot of opinions here. All good ones.<br /><br />I use somewhere between 30 and 40 to 1 in my '57' 7.5 Rude. It ends up that way because I'm never mixing a bone dry tank.<br /><br />I've been doing it for 10+ years. THe difference in smoke is quite noticeable from 24:1.