All:

Some notes from my experiences.

Four stroke engines:

Saito: I have a bunch of them, excellent engines. Powerful, long lived, and not expensive to operate or overhaul.

OS: I have had a bunch of them. Thankfully, they are all gone. Terribly overpriced; the Magnums are the same for a 60% lower cost.

YS: If you want the ultimate 4s engine.

Two stroke engines:

Cox: They've lasted more than 50 years on the market, they have to be good to do that.

Fox: Don't like them. In the old days the 29X was the engine for c/l "B" speed, but you had to take a spare or two to a contest, they didn't last long. The stunt and rat race engines broke cranks with distressing regularity. I understand the later ones are much better, but I'm not going to buy one.

HB: Good engines, but they don't stand up well to a lean run. The rings aren't expensive, that's all it usually takes to get one back to peak, provided it's a 21 or larger. The smaller ones are lapped piston. You cook it, you toss it.

K&B: John Brodbeck is as nice a fellow as you will ever meet, his engines are the same. The old two needle "Block" carb wasn't hard to adjust, but you did have to do it right.

Magnum: Never had a bad one, my C-3/10 has a pair of eight year old XL 46 engines, still run like new. The GP 25 on my Eaglet is still purring after some 20 years. I have several of the XLS engines also, not the first problem.

MDS: Only have one, it has never given me any reason to be sorry for having bought it.

Norvel: There is a pair in my Tiggerkitty, they are just about due for replacement. The left is down several hundred rpm on the right engine. I wont fly it again until either there is an engine change, or I find a reason for the low rpm.

OS: Currently have five. I will not buy any more. The Magnum is a better engine for a lower price. OS has gone to ABN cylinders, they are just not as good as the ABC cylinders in other brands. The "Environmental" excuse horse crap is just that: horse crap. They have deliberately cheapened the engines. I really believe that if Shigeo Ozawa were still alive they would never have gone to ABN. Environmental considerations? No. Saito is still ABC and AAC, OS is the only Jap engine that has gone to ABN.

Rossi: Great engines for fast planes, but heavy for sport planes. I don't have any now, but all I've had have been good.

Webra: An under rated engine. They wont disappoint you.

Bill.