Dick, "purpose built" is a very relatively term. Zenoahs are "purposely built" for RC as much as many of the newer gasser brands are. The difference is mainly in their retaining the heavy mageto ignition. I'm sure you're aware of the fact that even some of the most prestigious (mostly American made) gassers that won tournaments and such also have rather humble industrial origins. As long as they are well designed and converted, these chainsaw heads do just as well as those European brands with supposed pure pedigree.

Then again, those thoroughbreds don't always perform up to their billing, either. I was very surprised to read the ZDZ50RV review by Clarence Lee in the August '03 RCM. The rather low 6.86:1 CR didn't jive with the pompous advertizement of high CR designed for high octane. Disappointing too was the 59.6 Oz weight - my Poulan 46cc with a very similar BCM muffler weighs right at 60 Oz. And that's before I make any attempt at lightening up the engine further, which is easily done given the generous cooling fins on it.

Most importantly, the power output wasn't near what I would expect from such a race horse. The ZDZ50RV only bested the lowly Poulan 46cc on CH Ignition by about 200RPMs.

As is often the case, "purpose built" is in reality mostly "purpose marketed". Unfortunately, unless someone like Clarence Lee spills the beans, most of us have nothing more than the manufacturer's words to go by.

So, how about those HP & Torque curves, huh?