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Old 07-27-2022, 11:04 AM
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Originally Posted by franchi View Post

Today, I was testing for ether content by the following method.

I expose a given amount of fuel to the Summer Sun, 91 degrees for an hour and measure again to determine the amount of mix that disappeared. I assume that what is missing is the ether contention . Is this method an accurate way to determine the total ether percentage in a mix?


I realize and hope that you probably solved the fuel problem by now, but I wanted to give some feedback on the original question.

I pour some unknown diesel fuel into a 10cc cylinder, 2cc or so fuel is good to make a fairly accurate assessment. I wait for 2 days for good measure, at which time all of the ether is gone and the castor oil is separated from kerosene and all three components can be measured. I'm not sure how ignition improver affects this but it is in very small amounts so it really is not an important error source. In my experience, 1 hour would be too short for all the ether to evaporate even in hot weather.

As for fuel mix, I use 40% ether, 28% lamp oil, 30% castor oil and 2% Amsoil for all engines below 2cc, except for my Letmo 0.6cc replica which won't run reliably with anything other than 70% ether and 30% mineral oil .