Just picked up a 2013 Rotax FR125. Switching over from aircoled 100 cc KPV so I can particiapte in more racing. In the KPV I exclusively ran Burris Castor during warm months and Burris Blend as weather got colder.
I have about 1/2 a case of each left over and was wondering if it is OK to run the Castor and Castor Blend in the Rotax till it is all used up. When used up I have no issues switching over to a full synthitic like Motol Karting.
At this point I am not concerned with peak obtaining peak performance, just want to make sure running the Castor Oil does no harm to the engine.
If you run Rotax series you have to run their oil, if not you can run whatever you have.
If your engine is sealed, I would not run castor as you can not get in there and clean the ring and piston, just buy some Motul or XPS and you are good to go.
It wont do any harm perse, other than perhaps gum up the ring and or powervalve sooner. Arguably it could affect your jetting too.. Probably the biggest debate would be on issues that might occur when you switch from castor to syth.
Just go with the Motul or XPS. You could sell the castor on ebay or EKN or something. Keep a bottle or two for the KPV if you still have it.
Castor will do you no favors in a Rotax. It can really muck up the power-valve, and it will certainly throw jetting off. Both of which are critical for having a ‘fun’ time in a Rotax kart. Motul or XPS are your best choices.