1968 Erude 40hp Lark - fuel type.

[jai070404]

I understand to use a 50fuel/50oil mix. Since my motor has been idle for 9 years I will start with 40-35fuel/60-65oil.<br />My question is about octane. We have four major variants in Australia. (why do you call it gas when it is actually liquid?) Normal unleaded fuel is 91/92 octane. Premium unleaded is 96 octane. High octane unleaded is 98 octane. Lead replacement fuel for vehicles built before 1986 is 96 octane. Which is best for my motor? Thanks.

 

[alcan]

Re: 1968 Erude 40hp Lark - fuel type.

The ratio for your motor is 50:1. That is 50 parts gasoline/petrol (gas) to 1 part oil. So for 50 gals of petrol you need 1 gal of oil. Or 50 liters of petrol 1 liter of oil. Use the lowest octane avaiable. Our octane rating in the U.S. are in the eighties, but I guess it depends on what rating system is used. The numbers displayed on our pumps are there so the comsumer has something to look at other than the price. They mean very little.

 

[jai070404]

Re: 1968 Erude 40hp Lark - fuel type.

Got that ratio completely mixed up didn't I? Someone suggested when I first fire this engine I should start it with a 35:1 mix to quickly get it lubricated. Does that make sense? Thanks.

 

[JB]

Re: 1968 Erude 40hp Lark - fuel type.

It would do no harm to run as rich as a 24:1 mix for the first tank after a long layoff, Jai. After that go to 50:1.<br /><br />Your 91 octane gas is equivalent to our 87 octane unleaded, which we recommend.<br /><br />Good luck.