As I see it, the masses usually have it right so with that in mind, when BASED SOLELY ON RELIABILITY, Which is the best 4 stroke 90 sized engine around?

This is not a realistic poll. I have a Saito 100, a YS .91FZ and an RCV .91 SP, all are totally reliable. "other" should be excluded. If I could have the option, I'd vote for all the above except the pumped OS .91, the Magnum and other.

My Magnum 91, which is not pumped, starts well and is without problems.

I think you can vote for all 3 if you want... As for realistic, the fact that I made it makes it real not to mention that I have to pick one of these in the coming days so it is very real to me... I can understand liking more than one in this category and I could use your details on not picking the pumped 91 (front runner 4 me right now) more than your critique of the poll itself...

If you included the YS 110 and the Saito 100 because you're considering them, one of them would be the logical choice since the day will come when you'll want a more powerful engine. Performance wise, there is more difference in performance between the Saito 100 and the .91 than the .09 difference in displacement would indicate. Powerwise the YS 110 is the hands down winner.

PS, as to the OS .91, I would pick the simpler of the two.

Im familair with the listed engines but the RCV. I heard some good things about the design. How is it compaired to a saito .91? Same power, swing a larger prop?

The Saito .91 turns a 14x6 for example at about 10,000 rpm or close to it, the RCV .91 turns a 17x6-10 fourblade at 5,500, in reality the RCV would be better off with a 17x10 fourblade at 5,000 rpm.

The word I heard on the RCV SP series is that they run heavy on the power to weight ratio. I have heard nothing about the regular series but would like to...

I only have the .58 CD regular engine, it turns a 13x6 at 9,000, it is very compact.

I have all these except the Y-S 110 and the OS with pump. They are all good except the OS 91 With the pump. And that is only because OS will change the design and you cannot get the special parts or they will want more than a warrented amount for a regulator part or the pump.

(I've never seen a RCV 91)??

Enjoy,

Jim

Looks like the Saito AAC 91 is the best bet so far... I am surprised because with the 100 being the same frame, it is hard to imagine people wouldn't opt for the extra power...