Hi, I have 18' 1990 Chaparral 1800SL with 3.0 Mercruiser
Motor and carb and outdrive has full rebuild over last year, compression is perfect in all 4, starts and runs perfect. New plugs, cap, and all that tuneup stuff, timing and all...
I had 17 prop and it only gives me 26-28mi/h(GPS) at...