1975 Evinrude 70hp

jhetrick55

Petty Officer 3rd Class
Joined
Apr 21, 2017
Messages
83
I boat my first boat last fall. Mostly the boat has run well with a '75 70hp Evinrude. But, it starts somewhat hard. Once it is running it seems to run fine. I have check the carbs and they seem like they're not the issue. But I did some digging and found very minor scoring in the center cylinder. I am wondering if it maybe was overheated some time before I got it and if I should be worried about minor scoring like that?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,433
I do not believe there is such a thing as " minor " scoring.-----Motor should be taken apart.
 

David Young

Chief Petty Officer
Joined
Jul 12, 2015
Messages
485
My 1977 70 hp wouldn't start because of 'operator error' when I got it a couple years ago. After learning the proper way, it starts on the second or third cranking. Every motor has its own starting quirks, once you find out yours, your motor will start without any problems :)
 

jhetrick55

Petty Officer 3rd Class
Joined
Apr 21, 2017
Messages
83
My procedure for starting the motor is to raise the warm up lever all the way, push in and turn the key for short bursts until it fires, then lower the warm up lever to a reasonable RPM so it warms up.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,433
Some will argue.---Starter and battery must be in top notch condition.-----Those motors in good condition start up no problem in the first try.
 

jhetrick55

Petty Officer 3rd Class
Joined
Apr 21, 2017
Messages
83
I had it out last weekend and it did better. Since I found the scoring I am using a little more oil in the mixture and 91 octane recreational vehicle gas. Also, I notice on the muffs it seems to idle fine, I am guessing with less back pressure. In the water I am going to adjust the idle to make it a little higher because sometimes it dies shifting into drive.
 
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