I went to the hobby shop near school last week and accidentally bought the wrong fuel I had been using.  The fuel I bought is 15% Nitro, and 18% all synthetic. Would this fuel be ok to use in the hot Florida weather for the LA 46 or should I take it back and get 10-18 (which is 80% synthetic, 20% castor) which is what I had been using down here.

Thanks!

Lubricant technology is changing as we speak.  There are advantages to synthetic oil as well.  No castor gumming, varnish, smell on your clothes etc. I don't hear anybody bragging about putting organic multi grade lubricants in their car, except for air cooled VWs. 


Castor is a vegetable oil and was never a good oil for long term crankcase applications. In spite of all the new synthetic technology, all of the worlds top race teams running two strokes still use castor or castor/synthetic blends; that includes motorcycles, go-karts, outboards, speedway motorcycles (4-stroke, but total loss oiling system) and the top F2D combat team fliers. Why? because it gives the best protection under high heat/high load conditions.

Lubricant technology is changing as we speak.  There are advantages to synthetic oil as well.  No castor gumming, varnish, smell on your clothes etc. I don't hear anybody bragging about putting organic multi grade lubricants in their car, except for air cooled VWs. 


Castor is a vegetable oil and was never a good oil for long term crankcase applications. In spite of all the new synthetic technology, all of the worlds top race teams running two strokes still use castor or castor/synthetic blends; that includes motorcycles, go-karts, outboards, speedway motorcycles (4-stroke, but total loss oiling system) and the top F2D combat team fliers. Why? because it gives the best protection under high heat/high load conditions.

I would like to see some data on current synthetics versus castor.  But whatever works for you is fine.  Certainly if someone has a reworked motor they should run what the builder tells them to run.


     I would never get in a "what's the best oil" debate. I was just posting the data so folks can understand why castor does what it does.
     The data I posted is current. The very latest two-stroke racing oils from Maxima, Castrol, Silkolene (Fuchs), Yamalube, and Repsol use varying combinations of Castor and Ester based synthetic oils. There are some Ester based synthetics that are supposed to be superior to the others but they are very expensive. Also, Ester based oils do not play well with Methanol and Nitro so are used for gasoline fueled applications in two strokes.

As for the comparison with 22% 50-50 versus 22% synthetic, there have been a lot of tests run and the results are generally: When the engine is four-stroking or two-four and even in a very wet two-stroke, the head temps will be the same. When you start to approach lean-best power the head temp with all synthetic will rise considerably faster than the 50-50 and if you go over the top until it sags badly there will be a large difference in the head temp. The chances of detonation are also greatly increased. (that phenomenon that makes the head & top of the piston look like they got sand blasted)