Why not RCU and OS? Why rule out Thunder Tiger Pro?

http://www.rcuniverse.com/market/item.cfm?itemId=606181

This is new, I haven't heard complaints about these at all, and it's nearly half the price of an OS with no measurable loss, in my experience.
Tower quality has issues in their engines, read the comments here.

http://www.rcuniverse.com/product_gu...m?engine_id=42

This is the best tool I use before buying anything I'm not already familiar with! What you could do is buy the Tower muffler for $14 (GMS is the same as well) and throw it on the Thunder Tiger or the OS and see a gain in performance over the restrictive stock muffler.

I say go for it, I bought the tower trainer package with the .46 and have not had one single problem with it. I would buy another. Good luck.

You Tower Engine users, I am with you too. Have had mine for three years and have not touched the needle valve at all. It runs great and I have worn out 3 Contenders with it. That being said, I now have a problem. Sat. I came down a little hard on the spinner, but did not break the prop. Now it will not go to TDC without binding. I pulled the back plate off, no gauling. Pull the carb off, no sign of unusual wear on the crank shaft. Pulled the head and when I tried to pull it through the innerliner was forced up before the piston would go to TDC. The piston is black from so many runs, but I don't think this would affect it that much. Any clues to what de problem be or a solution. I know it is a pretty inexpensive engine and I have an OS to replace it, but it was for my beater plane and I would like to save it if I can. Thanks men.