1968 Evinrude

Hello All,<br /><br />Can some one please tell me the best oil mix, for a 1968 Evinrude motor???<br />I have tried 32:1, and it seems to smoke a lot.<br />I have heard that 24:1 should be used in pre 1970 outboards.

Re: 1968 Evinrude

Welcome to Iboats!<br /><br />Could you please describe your outboard more? The model # would be great but HP would be enough.<br /><br />All OMC (Johnson & Evinrude) outboards made after 1963 were rated by OMC at 50:1. But on a few smaller engines following OMC's recommendation is not the wisest policy.

Re: 1968 Evinrude

Hello,<br /><br />I have the 40 HP 1968 Evinrude!<br /><br />Thanks

Re: 1968 Evinrude

50:1 for sure on that sucker. Use 87 octane gas (US & Canada) and TC-W3 outboard oil.<br />If you still find it's smokey, you may have it running a little rich. Best bet is to "read" the spark plugs for high speed, and adjust the idle mix control on the carb for low speed.<br /><br />Finally, if you're running in colder weather you can expect a lot of steam out the back, which is sometimes mistaken for smoke.

Re: 1968 Evinrude

Hello,<br /><br />what is meant by "read" the spark plugs for high speed?

Re: 1968 Evinrude

It's a way to check the fuel/air ratio on each cylinder. It works like this: start & warm up the engine on the boat. Then do a couple minutes at full throttle (with the boat moving naturally) as much as conditions permit. Then quickly shut down the engine and remove the spark plugs. Keep track of which plug came from which cylinder. <br />Look at the plugs' porcelin insulators at the firing end. Both should look pretty much the same. If the insulator looks white, the engine is running too lean. Too lean will kill an outboard fast. If it's black with deposits, it's running too rich which will foul your spark plugs and waste gas. Tan or light brown, slightly damp is what you want to see.<br />If the plug is white like it's unused but wet with fuel that will indicate that cylinder isn't firing.<br /><br />Naturally, you'll need a newish set of the correct plugs for this test; Champion J4C gapped at 0.030"

Re: 1968 Evinrude

Paul Moir,<br /><br />Thank you so much for your insight.<br />you have put me back on track.<br /><br />I have burnt 2 of the 4 gallons that I mixed 32:1.<br />Can I add a gallon of gas to the remainder to lean it out, or should I start from scratch 6 gallons with 15.36 oz oil??<br /><br />Thanks,<br /><br />Ade

Re: 1968 Evinrude

Hi, according to my math 1 gal would get you to about 48:1 which ought to be close enough.