What size prop are you using on the Tower .40? Anything larger than a 10x5 or 6 will load it down too much. Try a 10x5. You will be amazed at the difference if you are running an 11" prop currently, or more than 5" of pitch. This engine likes to rev up, unlike many of the other plain bearing engines out there. Also, if you aren't using a fuel with 20% oil, half of which is castor oil, it will make the engine run hot and doggy.

As Jim, W8YE (I hope I have it right, Jim) said, the Super Tigre GS-40 is a strong running forty, despite its low price. And it doesn't need special fuel, as do most plain bearing engines, such as the Tower .40, OS FP & LA series, TT GP series, etc.

The SK .50 is another engine to consider. They run very well and are fairly powerful. Were it me in your position, I would buy either a Thunder Tiger .46 Pro, or a Magnum .46 ball bearing engine. Both are fairly strong and are dependable with the Magnum having excellent support from those that distribute such engines in the US.

Truthfully, the GS-40 and the G-45 are excellent engines too.


Ed Cregger