Why not?
The answer to that can't really ignore what the manufacturers are doing.
First, they're <i>not</i> doing it to increase frequency of sales. Do you think they like having to look bad by producing saws which don't last as long? No, the fault lies fully at the feet of the EPA and OSHA (in the US) and similar agencies worldwide. Two-stroke engines have distinct advantages via less complexity and lighter weight, all while producing more power per time frame. But they also pollute more than their 4-stroke-cycle counterparts.
Our servants in government take the role of masters and force things down our throats all the time. Much, much too often. We can't have our saws be loud because that will harm us when we use them. Now vibration is entering the regulated scene as well.
We can't have unburned hydrocarbons being emitted into the air we breathe, especially while cutting down the trees that do most of the work cleaning that air. So the mufflers must retain enough heat to ensure the wasteful two-sroke-cycle engines pollute the least amount possible.
I don't believe you can be fined for operating your modified EPA-regulated chainsaw in your own yard, but you cannot legally operate it on Federal (and likely State) property, and your mechanic can be fined for working on it without restoring it to approved configuration. Practical reasons for "why not?"?
Probably nobody here will complain about equipment becoming lighter, more fuel-efficient, and vibration-free. Perhaps in time a method will be put into place whereby saws can once again breathe better while remaining both quiet <i>and</i> emissions-compliant. I've heard about reed valves in the transfers (see the bolt-on covers on Huskies, which are probably for production <i>and</i> emissions purposes) through which a shot of straight air precedes the fuel charge, so the portion which escapes out the exhaust port before it closes will not contain raw fuel, but only air. Time will tell if that and/or other schemes will solve the problem.
Glen
