ORIGINAL: airbusdrvr
Impaciq, you wrote, "The biggest thing to remember though about YS engines is do not use a after run oil that is petroleum based as it will cause the seals in the regulator to swell." I suppose this is a dumb question, but what about Hobbico after run oil? I suppose Marvel Mystery Oil is also petroleum based? Is there a product similar to Ultra Oil available locally, ie auto parts store?
I can not comment on the Hobbico oil as I have never used it or had a bottle of it but the Marvel oil is petroleum based. You can use oil that is 100% synthetic as mentioned here already (mobile 1) with good results. Just make sure it is 100% synthetic and get the lowest viscosity oil you can if going the automobile oil route. I believe 5w30 is the lowest one can get over the counter. IT will not take much either! I have always used Ultra Oil and one bottle really does last a long time.