1965 3.5 hp evinrude ? Fuel mixture?

[Barry Gardner]

I picked up a sweet little motor but want to confirm it's
year and fuel mixture.

Mod# 3502A
Ser# B34140

If you can help me ?
Thanks

Barry

 

[tx1961whaler]

Re: 1965 3.5 hp evinrude ? Fuel mixture?

50:1 for motors after 1964, BUT, here's chinewalker's view from the engine FAQ:

POST-1964 JOHNSON/EVINRUDE/GALE - The official stance on 1964 and newer OMC engines is to run them 50:1 and it's a good rule of thumb to follow on the bigger motors. OMC also renegged on the late 1980s 100:1 recommendation on the smaller (4-35hp) motors, bumping them back to 50:1. I've found that the smaller (3, 4, 5, 6hp) motors from post 1964 up into the mid-1970s may appreciate a bit of extra oil as they still have some bronze sleeve bearings. I run 40:1 in my '72 4hp, as I have a pile of holed blocks, burned cranks and twisted rods that were run at 50:1.

A little extra oil will not hurt your engine.

 

[1946Zephyr]

Re: 1965 3.5 hp evinrude ? Fuel mixture?

Yea, I have a 1970 4hp myself, which I replaced the crank and rods, due to too light of oil mix. These were actually still built like the old 3hp Lightwins and would be better to have no less than 24:1 I know all the 3hp's would be best at 16:1, because they have absolutely no needle bearings at all. Did they build a 3.5hp in the 60's? I never heard of one. Your model number actually goes to that of a 3hp and those do run at 16:1.

 

[F_R]

All 1965 Evinrudes were designed to run on 50:1. Can you run it on more oil?? Yes, of course you can. However, that motor has a fixed high speed jet, calibrated to run 50:1. An extreme variation in oil content can result in an improper fuel/air mixture being delivered to the engine.

We can, and probably will, be arguing the subject till Doomsday comes. Meanwhile, Evinrude said 50:1 for 1965-up. There sure are a lot of them still running out there.

http://www.old-omc.de/e_1965/seite_03.jpg

 

[1946Zephyr]

Re: 1965 3.5 hp evinrude ? Fuel mixture?

Except for the 3hp, of course. All motors in 1965 were set up with needle bearings except for these little guys. You don't want to run those lightwins with anything less than 24:1. The end result will be ugly.