Evinrude 100hp 1632cc do I MIX 2cyl or 4cyl oil

[19611starcraft]

Hi i just bought a 18ft starcraft holiday with a evinrude 100hp 1632cc outboard,I see there is 4 spark plugs so jam guessing its a 4cyl engine but not sure if i should be mixing 2 cyl or 4cyl oil into my gas.Is 50-1 the right mixture and are these motors reliable i think its mid to late 70s

 

[RCO]

Mix 50:1 with TCW-3 rated 2 cycle oil. Should be a reliable engine if well cared for.

 

[jakedaawg]

4 plugs means 4 cylinders. Not 4 cycle or 4 stroke.

 

[19611starcraft]

ok so use 2 stroke oil and is there any known problems with the evinrudes from 70s

 

[jakedaawg]

They dont like to keep their piston rings. And the hood latches ground out poorly routed plug wires

 

[interalian]

ok so use 2 stroke oil and is there any known problems with the evinrudes from 70s

Yes, and specifically use outboard 2-stroke oil rated TCW-3. 2-stroke oil for chainsaws or lawnmowers will gunk up the motor.