If your new to engines stay away from the Tower motor. You have to setup the high and low end and follow a full page of break in instructions. I never got mine to run well, you continually have to play with the settings.

The TT pro 46 is a sure deal. For the price it cant be beat and it is super easy to setup. Normaly all you have to do is run a tank or 2 through on the ground and set the high end needle valve. I have 2 of these engines and have yet to touch the low end settings and they idle great.

However, the stock muffler on the tower engine is great. I would be more inclined to buy the TT pro 46 and then buy the tower muffler seperate than to buy the Tower engine.