Can anyone advise me from experience -I just bought this boat and motor running rough and stalls at low idle. Brought it to mechanic and he states i have 110 psi in all cylinders , 1 bad coil and diaphragm in fuel pump no good,. it runs hot at and idle and gauge is at half way mark when cruising, therefor he say change impeller and thermostats (2) Its a 94 150 hp merc 6 cyl 2 stroke w/carbs. just thinking if i should re power with Suzuki ($19,500) or Yamaha 200 ($?) 4 stroke or invest $1500 cause he says this merc is sought after by many racing guys cause they are very good motors. Any suggestions?