200 hp. 1997 johnston keeps blowing the power head base gasket & water leaking out. This gasket has been replaced [4] times in past 2yrs. 1st shop said after they replaced the 2nd time that it must warped & saif they sent to have plained. then they went out of business. next season it started leaking again, took to different shop & they said it had not been cleaned properly by 1st place & old pieces of gasket still there. Thought they had something as everything fine for 3 mths and then it started leaking again. Anyone experienced problems with this engine & simalar problem.