I just got a used saito .72 and im disappointed with its power. I have it on a .40 size twist. Im using 15% cool power and it only turns 10,600 on the ground with a 13x4W prop. It took about 3/4 throttle to hover. Does that sound right or is the engine beat. The compression feels ok but im not sure if the bearings are. I checked the valve tappets and they seemed pretty close to wear they should be.

Thanks for any info in advance.

You are in the ballpark of what the engine will do. It will have a little more power on 30% fuel and turning a 14x4W.

David

I have a Saito 72, on an Atec Excel (similar size to your plane) running an APC 13x6 on 15% Cool Power. I get 10,400 and am happy with it. So what if it takes 75% throttle to hover? I think you have the right size engine in the plane and it is performing where it should be.

The engine sounds perfect. The problem is the plane. The Twist is no lightweight! If you put that engine in a 4.5lb Mojo it would be a rocketship! Weigh the Twist when you have a chance. I bet it is well over 5lbs RTF dry.

Lose that 4 pitch prop,, Mas K 13X6

and Lose the porky Twist

first of all cool power sucks. go with byron fuels ( 20% ) the prop is fine for 3-d but if you want the best prop size i would keep the pitch but add one inch to whatever the recomended size is. byron fuel are blended specificaly for four strokes thus it will reduce the amount of unburned resedue on your plane.

you can never be disapointed with a saito

It sounds like the engine is performing fine. Try an APC 13 x 6 and see what you think. On my Ultra Stik 40 and U Can Do 46 the overall performance (to me) was always better with the 13-6. Running Powermaster 15%.