Is 16x6 too much for Saito 100? The manual recommends 14x8 ~ 14x10 and 15x6 ~ 15x8 ... I figured 15x8 and 16x6 would have similar load. How does this sound guys?... thanks

Depends on what you plan on installing the engine in. But I have have a Saito 1.00 and believe that the 16 inch prop would be a bit much unless you are using it in one of the 3D stlye of models, then go with a 16x4 APC.

its for a TF Mustang 1/7th, I think a war bird looks better with bigger props... and I already have a 16x6 prop, I dont want to get a new one unless I really have to, I'm only 19 dont got too much money for a $15 prop.

Saito 100's run very nicely on a 14x8 or 15x6 with RPM's somewhere around 9500 (assuming at least 15% fuel). A 16x6 has a bunch more load than these and will probably drag the engine down into the 8000's. Not good for a Mustang that will probably want some speed to fly nicely. In fact it could make the maiden very interesting.

I recommend that you spend the $15 and get a 14x8 or 15x6, at least to start off with. Its a whole lot cheaper than replacing the whole airplane.

Also if the engine is new then read up on how to break it in. The 100 is a real shaker the first tank or two, and most need a half dozen tanks or so and a good bit of adjusting on the low end before being ready to fly.

Too much prop. For the mustang I'd go for a 14-8 3 blade prop