Removable head on a Saito? methinks this guy is somewhat confused.
Re synthetic oil in Saitos. Latest info I have (on latest engines, 54, 62 and 115) all say use synthetic only. That is on Saito produced data that came with engines. Also please note the required percentages of oil to be used, different to the "old engines" Me I gave up castor in any of my engines (except diesels) years ago mand not suffered any problems in doing so. In fact by the use of different viscosity synthetics I have been able to get better performance out of the "racing engines" That statement comes with the rider that viscosity change was only one part of the mix and I had the use of sophisticated equipment to measure the changes.