Re: Fuel Mixture for 1963 18 Hp Fastwin???

Posted by Ed Mc. (67.250.189.69) on October 17, 2003 at 16:53:14:

In Reply to: Re: Fuel Mixture for 1963 18 Hp Fastwin??? posted by Chinewalker on October 17, 2003 at 13:46:50:

I second that, this year 18 is "fully jeweled" (has either needle, ball, or roller bearings on all the rotating internal parts), and there's no reason why you have to run a rich oil mix.

The main reason to run rich on an older motor nowadays is if the motor was built with babbit bearings/bushings internally, as were quite a few of the old 5.5 and 7.5 evinrude/johnson's, among others. These motors still must use the rich oil mix or damage to the rods and crankshaft will occur. Needle, roller, and ball bearings require much less oil than a plain bearing does.

In the past I've run the living tar out of some 'Fifties and 'Sixties OMC motors and Mercs, using mfr's 50:1 TCW-(###) oil and good gas (NEVER gasohol), and have had no problems. Just be sure of the internal construction of your motor.

The best oil they had in the Pre-50:1 days was 30 Weight and you had to mix it rich because it didn't provide the protection of a 2-stroke outboard oil.

When Mercury introduced their Quicksilver oil it was something indeed, but the fact of the matter is there's little if any diff in quality of the bearings in a 1950's Mk 25, MK 55, Mk 78, Merc 1000, or a later 25, 50, or 100 HP.

If you feel paranoid, a 30:1 mix in your 18 won't hurt anything, you'll just have to adjust your mixture needle(s) accordingly. Don't use bargain-basement oils, they don't have the additive packs that the mfr's oil does. I generally use OMC oil and have had no problems. Synthetic is best if you want to spring the $$$ for it.

Be sure to use Seafoam or a similar carbon-cleaning fuel additive to keep the fuel system clean and the rings happy. www.seafoamsales.com

HTH........ed

	Durafix Aluminum Repair Rod Demo