Thought I would give the AP one more shot, so I dumped some 30% nitro I had into it, and it only brought the RPMs up 15,000. Still a far cry away from the 17,000 that the guys with the OS engines are running. Oh well called Starfleet Hobbies, they have an OS .15 in stock, I am picking one up tomorrow. Anyone want to buy a hardly used AP .15 Yellowjacket?