the super tiger .90 is the best engine- it is more powerful than the saito 100 and will turn an apc 14-6 at about 11,000 on the ground. it takes breakin like the saito. uses 10% fuel runs great. tower has them for $129 now - hard to beat this engine. if you want it a little quieter get a bisson pitts muffler- you lose a couple hundred rpm but gets nice mellow tone. still it will fly the 4 star at least as well as the saito 100. at least for the typical maneuvers the 4 star usually does.

ed