Not repair related...yet...Johnson 70ELCNB

[Jermy-Jinky]

My boat has a 1982 Johnson 70hp J70ELCNB 2 cycle motor. I'm in the process of rehabbing everything so I haven't had it in the water, or running, or anything yet (it's the first boat I've owned if you don't count my Polaris Jet Ski as a boat). So...here is my dumb rookie question...Where do I put the 2 cycle oil? Do I mix it directly with the fuel in the fuel tank? My boat has a built in tank, not a portable. Or is there possibly an external oil tank to look for and the motor mixes it itself? I'm planning on draining and changing all of the fluids and fuel, but from what the gas tank smells and looks like now appears to be straight gas, it looks golden in color, not bluish tinted like most mixed fuel does.

I apologize in advance...I've not had a lot of free time to tinker around with it; 2 house rehabs are taking up my "free" time...hopefully I'll get to tinker this weekend (fingers crossed)...if I can get this old motor running, I'll be super pumped and know that all is not wasted.

 

[oldboat1]

Probably not VRO, but not sure. For testing, I think I would use a known good portable tank with 50:1 mix (2.56oz per gallon). No point in mixing up too much -- would do a gallon at a time.

On the main tank, check it for contamination (mainly water at the bottom). You may have to dispose of it. Additionally, if the prior owner did not use a mix -- and should have -- there may be more serious problems.

 

[racerone]

VRO did not come out until 1985 on the 70 HP I think.-----So mix the oil in your fuel tank at 50:1 ratio.-----Install a new water pump impeller before you launch the boat.----Perhaps read an owners manual before launching the boat.

 

[Jermy-Jinky]

Probably not VRO, but not sure. For testing, I think I would use a known good portable tank with 50:1 mix (2.56oz per gallon). No point in mixing up too much -- would do a gallon at a time.

On the main tank, check it for contamination (mainly water at the bottom). You may have to dispose of it. Additionally, if the prior owner did not use a mix -- and should have -- there may be more serious problems.

I'm planning on draining the tank regardless of what's in it. Is there any tell-tale signs/symptoms that show if it has been run on straight fuel instead of mix?

 

[Jermy-Jinky]

VRO did not come out until 1985 on the 70 HP I think.-----So mix the oil in your fuel tank at 50:1 ratio.-----Install a new water pump impeller before you launch the boat.----Perhaps read an owners manual before launching the boat.

Thanks! I have a Johnson service and repair manual that I found and downloaded, I'll look and see if I can find an owner/operator manual as well.

 

[racerone]

Post results of a compression test .----Should be around 14o PSI on a motor in good condition.----That motor in good condition will last many years.----It is simple to operate and maintain.----As a novice boater you need to accept that there are many things to learn about the operation of a 2 stroke motor.----Also install a new water pump impeller before your first fishing trip.---Test the overheat alarm too.