ORIGINAL: wjvail
Aren't you pushing those oils because you sell them?
I sell oil. I'm a distributer for Klotz. I'll sell you whatever you want. I buy both synthetic and de-gummed/fortified castor in 55 gallon drums.
I've run model engines for 40 years. I own over 300. In the beginning there was only castor. Then there was bad synthetic and castor. Now there is good synthetic but many folks remember the bad synthetic.
While I run a blend of mostly synthetics with some castor, I've had great success with all synthetics. I run some castor because of all the corrosion inhibitors I've tried, castor has been the best over time... and, because others think you have to have some castor in your fuel for it to be good fuel.
If you'd like to run Duke's fuel (28% oil all castor) I think you should. It ain't right for me but that's the beauty of this hobby... If you insist on running your engine lean, castor's your ticket. The pressings of this bean will form a thick, black varnish on you engine and save you from it's misuse. If you've been in the hobby a while, I think you'll prefer synthetic.
I personally don't find the engine pictured in the first post acceptable. If it was run properly and castor did that to it, that is unacceptable. If it was run improperly, synthetic probably would have protected it but if it didn't, you should learn how to run a model engine. In other words, to say that this engine was saved from destruction by castor does not excuse the fact that it was mishandled.
If you are in the habit of butchering your engines, please run castor. If you are not in the habit of butchering your engines, run synthetic.
Adjust opinion to taste,
Bill Vail