ORIGINAL: aaviles
I am a little confused as for that motor is better to use in a jet since I was looking at the specifications of the OS .91 RPM 2K to 16K
and the specification of Jett .90 are 15k wit LX muffler.
Those are not specifications per se, simply an operating RPM range. The numbers mean absolutely bugger all, zero, zip, nada because there is no mention of the load the engine is turning at that rpm. If you looked at a .15 with a rating of 2k to 16k, would you think it had the same power output as the .90's? Point made I think.
This is why numbers like that are listed - to obfuscate the issue for consumers who may not realize there is no standard load being applied to the motor, and who then might make a decision based on the numbers they read.
That is why Jett's ratings are, in opposition to standard practice, meaningful. They list rpm with a specific load, and that allows you to make an objective comparison if you have the same data for another engine. Or to compare between the various Jett models.
They are a top drawer motor, strong as blazes, beautifully made and robust, top notch carburetion, lessee, what else? Well, you get what you pay for is the basic truth. So if it doesn't kill you too much to plunk down the dough for one, it is highly unlikely you will be disappointed, and highly likely you will be as happy with your choice as the others who have chimed in with their support. Plus, you have the honor of NOT having a run of the mill engine at the flying field, so you ge to answer all those "what's that?" questions.