hi Lee, i have been on the engines threads and talking to some of the OLD TIMERS and a bunch of them convinced me to use at least 4oz of castor in 1 gal fuel and do what ive been doing and these engines should last a lot longer than my approx 26hrs that i got on my saito 100. theres some pretty knowledgeble guys there that been doing this for up to and beyond 40 years and have some pretty old orignal saitos so im giving them the benifit of the dought and there probley right. i hope so i dont want to have to whine like that again, i was starting to embarass myself.ha ha!!!

Gary