Tower Hobbies 75 engine is looking good! I bought one of these to try, as I wanted an inexpensive power plant with more punch than a 60 for my new GP Stuka 60. The recent comparison tests of the 60 size engines also placed the Tower engines in the top as far as power and price. For $10.00 more than the 61 I went for the 75. There are the usual production issues. The throttle barrel wasn’t turning smoothly and seemed to be scraping. I removed the throttle barrel and found slag at the bottom of the throttle barrel. I polished it out with a Dremel polishing bit and it now operates smoothly. The next problem is that the muffler bolts mount from the muffler side into the engine casing. This means that in order to tighten down the inside bolt I had to cut down the L part of an Allen key. It is also true that the engine is very tight out of the box and in order to get the engine to turn over the first time, you need to heat up the head with a heat gun immediately prior to starting. Once you have a tank through it however, it will turn over the same as other 60/75 engines. During the first tank run the muffler bolts and the fast speed idle screw assembly started to come apart. I used lock tight on the needle valve parts and shake proof washers and lock tight on the muffler bolts to solve these problems. I used a Kaos 60 for the test bed with impressive results. The engine starts very easy, has tremendous power and transitions well. With an APC 12-6 on the nose I tested the vertical to see how far it would go. I had to stop the test, as there was no sign of the plane slowing down and I was losing sight of it on a clear day! I checked the fuel usage on a 16 oz. Tank after a high speed 8 minute flight and was happy to see that it had only used about ¼ tank fuel! Good power and fuel efficient as well! I made a slight carb adjustment for my second flight on the Kaos and the engine ran just as smooth but had a lot more power. I am now confident that this engine qualifies as a reliable and powerful warbird engine!