Marada92
Petty Officer 1st Class
- Joined
- Jan 14, 2011
- Messages
- 223
After searching for hours upon hours through posts with no luck im turning to the wise members here for answers. Boat in question is a 1992 Marada 1800MVB 18' bowrider with 4.3 Mercruiser and alpha drive. I purchased the boat two years back and have had an ongoing issue with over reving. Prop that was on it when I bought it was a Quicksilver SS 14 1/2x 21p 3 blade and it would run high 40mph by gps but you could easily run it up to 5400rpm. Since I use this boat mostly for wakeboarding I switched over to a 4 blade solas 14 1/2x19p last summer, mostly to rule out a spun hub. First outing out I immediately ran it up to wot to see if the problem was fixed. Would run around 40mph and rpm wouldnt go above 4800 and pulled like a mule. So problem solved... I thought. Next trip to the lake right back to the same problems! Could easily run it up to 5500rpm if I tried. Could back it down to 4800 which was about 3/4 throttle and run around 30mph. So whats the possible problems. Tach accuracy is questionable since its the original one but that motor sure sounds to be over reving. Then theres the engine coupler but havent had any signs from it... no burnt rubber smell or any rubber in the bilge. Basically a brand new prop so thats ruled out for the most part. Only thing I have left is the anti-ventilation plate. I had a stingray hydrofoil on it and and replaced that with a set of smart tabs but never filled in the mounting holes. Could those holes let enough air to get to the prop and cause prop ventilation to justify the high rpms? Thanks in advance for any help I can get.
