piperj3 wrote: What oil and mix ratios do you guys run in the 57 Big Twins
24 to 1.
The newer 50 to 1 motors in their manuals suggest 25 to 1 if they are going to be run at high rpm for lengths of time.
Almost any 2 stroke will run fine on much less oil than their recommended oil/gas ratio. The damage being done is not detected until the motor fails and/or is torn down. They will even run fine with no oil for a little while.
It’s never too late to have a happy childhood.
I'm still pretty old school as far as fuel mixes for two strokes go. If I am doing my math correctly; if you start out with a completely dry 6 gallon outboard fuel tank, and pour in 1 qt of outboard oil, you can add 5.75 gallons of gas. This calculates out to about 23 to 1 fuel mix ratio.
All that higher math taken in to consideration, I try to start with dry 5 gallon fuel cans, pour in 28 oz of oil and fill to the 5 gallon level with gas. This gives me a ratio of about 22 to 1. All of my outboards seem pleased with this diet and I have had no plug fouling issues either. I get a fair amount of goo and drool, but as long as the motors are happy, so am I.
I also play with vintage air cooled go kart engines and on the bushing bearing Clintons I run mixtures as rich as 12 to 1, mixing castor with methanol. Even using the Nova ll points eliminator modules, still no plug fouling or hard starting.
Ever wonder why outboard fuel tanks are generally 6 gallon and all fuel cans/jugs seem to be 5 gallon? Beats me.
1957 FC Rocket -'58 Evinrude Lark 35
1958 FC Hawk 1-'59 Evinrude Lark 35 (and J-55)
1960 Starcraft 12' open boat-'76 Evinrude 25
1965 era McCorvey 3-point hydroplane-'52 Mercury KG-7H