Company out of Iola, Kansas called IMP made the Viper model for a few years. I had heard they went of of business, but not sure when. The Viper was one of the few offshore type boats they made. Most of their models were large runabouts 21-28 foot range. Not fast, but they rode will in Lake of the Ozarks slop. Raymonds Marine in Gravois Mills was one of the larger dealers around. They probably have service techs who could answer questions.