Fuel Mix

Responder59 · Post by **Responder59** » Sun Apr 23, 2006 1:50 pm

My Century with clutch has the number CPC 247L4. I run it on 10to1 mix but it makes a lot of smoke and tends to hunt at higher throttle settings.

I'm wondering if it would be safe to use less oil? An expert opinion will be greatly appreciated.

Post by **John@sos** » Sun Apr 23, 2006 10:01 pm

Hello there,
your motor is a 1964 Century plus and has the shorter bearing crankcase. From 1968 they fitted longer bearings and could safely reduce the mix to 25:1.

you have to be using Two stroke for outboards though, as I hope all are....

You will not get away with reducing it as far as 25:1 as the oil acts as a seal in those bearings as well as lubricating them. See the FAQ page for more, but I suspect you might get away with 16:1 quite safely.

It is not the lubrication that is the problem, simply sealing the case. you do not want to suck air in past the bearings, throws the mix out totally!

hope this helps.

john
SOS

CatiGull · Post by **CatiGull** » Tue Apr 25, 2006 1:05 pm

On fuel mixes etc.

I bought a 1 Gallon plastic gas can for mixing 10:1 for my Forty Featherweight originally - of course, since Seagulls like to Flock together and I now own 5 of them I have all different kinds of fuel mixes I have found optimal for each.

I bought a graduated cylinder and now just keep straight gas in the can, and figured out how much TC3 outboard oil to mix straight in the tank to get the correct mix for whatever engine I am using that day.

Ive found:

Forty Featherweight 1973 runs well on 25:1
Forty Plus 1977 Bing Carb runs on either 20:1 or 25:1
EFNR 1986 runs on 25:1 (i havent really tried this out on water since Im still fussing with the gearbox)
Forty Featherweight 1967 likes 10:1

and my Brand new 1963 Silver Century has never been run - waiting for my retirement party.....

I like that I can jsut dump the petrol in the car to get rid of it, and that I dont have to worry about it going stale.

When we cruise on our sailboat, we use a Forty on our tender, I just pump gas (manual fuel pump) from the main tank into the Seagull tank, then add oil appropriate for the motor...saves having to store another tank while cruising!