I am looking at a Catalina 31 with a 26HP Universal Diesel Engine. The max rpms are running at about 1900. The owner indicated it is a faulty injector and he is having it cleaned or replaced.Anyone heard of this problem? Is it a biggie?He seemed taken aback when I told him I would not have the boat surveyed until after this was addressed, and if he decided to clean the injectors that I would need that work warranteed in the sales agreement. Too hard? Not hard enough?