The problem with turbocharging is how the heck can you oil the turbo without a source of high pressure oil? Also how would the oil drain work? A really good place to look for small turbo is IHI turbochargers from japan, also hitachi, lombardini, and mitsubishi TD-02 could work. Also you would need some kind of valve on the exhaust to be able to build any kind of boost, and you would be pressurizing the whole crankcase which is what the 4-stroke guys try to avoid doing. Also the carburator would have to be modified so it wouldn't spray small pieces everywhere under boost. Also without an intercooler, the saw would probably detonate with only a couple pounds of boost. I have been thinking turbocharging a saw for a long time, but the oiling problem is the biggest thing holding me back.