I see more problems out of them (and the other 80 series) than I ever did with any of the prior models (except the 70 series). And we sold FEWER of the 80 series (far fewer) than any of the 60 series. The 60's were awesome, kawasaki engines. The 80's are Kohler's. I don't care for the Kohler engines at all. They seem to be sensitive to fuel. Fuel gets old and takes out the diaphragm in the pump, also plugs the carbs...makes the shutoff solenoid stick shut, etc. The drive belt and plastic idlers are sub-par (IMO) for larger yards. Deck is just ok. Not stellar, not junk either. LH blade spins backwards and has left hand threads-don't forget that if you purchase one and plan on you own maintenance. This applies to the 42 and 48". The sliding mulch plug is kinda cool. They drive pretty good as well. Fairly comfortable and all of the controls are easy to reach and use, including the KRA button. For a smaller residential yard they're pretty nice mowers but they are NOT commercial grade, they don't like to sit for much more than a month at a time, and they also don't last when folks are cutting large yards (+1 acre). I like them all except that Kohler engine. I'd rather it be a kawasaki.
