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| 1967 3hp evinrude lightwin |
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paul gedgaudas
New member
Username: uncle_paul
Post Number: 1
Registered: 11-2009
| | Posted on Sunday, November 08, 2009 - 03:28 pm: | 
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Hi, new to the site. I now have my fathers 1967 3hp evinrude lightwin. The service manual reads fuel mix "high speed mix 12:1" WOW! I don't recall dad running it that rich, I'm reading lot of opinions from 50,40:1,,,I'm willing to try what the book says. What do you think? MANY THANKS |
VicS
Advanced Member
Username: vics
Post Number: 747
Registered: 05-2008
| | Posted on Sunday, November 08, 2009 - 07:03 pm: |
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12:1 is a bit of a surprise. The current advice from evinrude is,
" The following is generally true: 1958 and prior used 20:1, 1959 thru 1963 used 24:1, 1964 and newer use 50:1"
See http://www.evinrude.com/en-US/About.Us/FAQ/Oil.Fuel.htm.
BUT with plain bearings throughout, no ball-races or needle bearings, I guess 50:1 would be asking for trouble.
See also THIS ITEM on the iBoats forums.
If it were mine I would not use less oil than 24:1 maybe even 20:1 but with modern oils it may not be necessary to use 12:1. If you try 20:1 and it does not run well then you will have to use 16:1 or 12:1.
The trouble with using a thin mix may well be not only the lack of lubrication but that there is insufficient oil to seal the crankshaft bearings (no seals you see) Also at these high oil levels changing the amount of oil may also affect the carb fuel/air mixture
British Seagull engines (Crude British made outboards) ran on a 10:1 mix originally. They also had plain bronze bearings and no seals. From the late 1960's when larger bearings were fitted they could be run on 25:1.
Look after it and it should serve you well even if my 1974 Seagull will serve me even longer. |
uncle paul
New member
Username: uncle_paul
Post Number: 2
Registered: 11-2009
| | Posted on Monday, November 09, 2009 - 07:29 pm: |
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VicS, Great info thanks so much. This site is awesome! |
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