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1978 Johnson 150 smokes excessively with proper 50:1 ratio mix

M

Mike Gray

New member
I have a 1978 Johnson 150 that when I mix the proper 2.6oz of oil to a gallon of gas it not only smokes excessively but will also kick back against the starter and not run. I backed off the mix last summer (took several mixes to get it right) to approx 2.1 oz per gallon, it still smokes (like a two stroke should) and I did not have and have not had any issues, but can anyone tell me why it does this with the "proper" mix??
 
If you reduce the amount of oil in the mix , then you reduce the life of the motor.-----------------Many motors from the 50's still run like new since they were properly lubricated with mix at 24:1.---------Marketing drove the reduced amount of oil.
 
Thanks for the reply racerone! I guess what I should of said is it won't start let alone run with a true 50:1 mix it backs up against the starter and I even melted a terminal on a brand new battery trying. I am running the evinrude/Johnson XD30 oil and measuring with a liquid measuring cup (I have an onboard tank). I don't want to hurt this engine afterall It has 105-110 compression on all six cylinders after all these years. Am I doing something wrong on the measuring or maybe it needs a tune up, I don't know, but it wouldn't run right until I lowered the ratio. It runs very well, smokes good on startup and while it is running. Please help if you can I put it on a restored 71' Glasstron V177 (customized) and I want it to last. Please help if you can!!
 
Plugs were new last year and have good spark. The bulb gets rock hard and I went through the carbs last year when I was having trouble. I have a manual for it and could check the sync but I will probably leave it up to a professional so I don't screw it up. Is measuring the oil with a liquid measuring cup the right way to do it?? I have an 18 gal. tank so I mix 5 gal. at a time in a can.
 
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