The carb on the SRM-261T is ADJUSTABLE !!! The adjustment screw is hidden under a "limiter cap" that is required by the EPA. The limiter cap is located inside the hole on the top of the carb... where the rotor is (part that swivels when throttle cable is pulled). If you have a GOOD dealer in your area, he should have a service bulletin that shows him (and you) how to adjust the carb. If you run 89 octane and a synthetic oil at the CORRECT mixture, keep your air filter clean, and keep debris from building up on the exterior of the carb.... you shouldn't have any problems or need any adjustments.
Here's the deal... you can thank the fruits and nuts in California for screwing things up! The feds (EPA) then follows suit. They've made emissions standards so tight on outdoor power equipment that they run on a very fine line now. Some companies have found ways to stay 2 stroke and meet emissions standards... others are trying 4 stroke and hybrid technologies (although with varied success). And guess what... it's only gonna get worse in the next few years. Ratcheting gas caps (like on your truck or car) are already on the way... as are non-permeable fuel lines, fuel tanks.... and those plastic gas cans we all like... they may go away soon too. Unfortunately, there's no fighting it...so just accept the change and make sure you do preventitive maintenance and operate your equipment EXACTLY as your operator's manual dictates.