25 minutes of run time without having to work on it is good for a Tecumseh engine. It was a great day when the Tecumseh on our blower chucked the rod. I put a Briggs on it and have not touched the engine in 10 years.
Due to the small amount of use a blowers sees, usually the carb is plugged with varnish. I recommend running Stabil in all fuel and running seasonal equipment out of fuel when done. That is what I do with my equipment.