bgriff

Took my first trip in my new ( to me ) 2000 29" fever and have a question about prop cavitation.... The boat has twin 350 mpi's and has hydromotive props but I'm not sure what size and pitch they are yet. The boat ran 70 easy at about 4700 rpm and with full fuel and 4 adults. It could do more with some triming etc so I think it is proped right. My question is... If I let the boat slow down to about 20 - 25 mph and start to loose plane, it cavitates and I need to slow way down to get going again. Is this normal or are the props wrong? Otherwise the boat ran excellent. I found that it seemed a little smoother at over 40 to 45 mph in 2 and 3 footers. Faster seems better than slower for sure but what would the best speed for optimum ride in those contitions generally be? I'm just beginning to experiment with driving techniques. I'm not sure if keeping a little tab in was better or not, maybe I did not use enough to get the smoothist possible ride. I kept the drives at about 2 indicated unless I was starting from very slow. Brought them out to 3 or so at higher speeds in flatter water. Any suggestion would be appreciated... It was a great day though. Quite a few go fasts showed up at Claudios!!! Too bad the season is almost over up here in New England.

pullmytrigger

At 25 my twin smallblock 29 falls off plane......and thats with the drives tucked all the way in and lots of tab.........at that point I have two choices......put the sticks to it and speed up or pull them all the way back and stop....my boat will not run 20mph at all......28 is about the slowest
Mines a non step but for max speed I trim to 6 (indicator goes to 7)
High speed cruise is about 5

gferdon

Just about identical to what PMT said with the exception of the drive position...my '04 is a single step and best speed is at 5 or just slightly less depending on water conditions. Just about all fountains want to go fast in rough water...almost always a bad idea to slow going over a big wake, I open it wide and fly her over (learned this the hard way!). Good luck with your new ride, hope to get to see it sometime.

G-

pullmytrigger

One of the best things I ever did was at the advice of some OSO members:
Take a straight edge, lay it on the bottom of your hull and out the back......now put your tabs down until they are paralell with the straightedge......that is your neutral tab position.......mark that position on your indicator (I think 3 on mine....I made a mark on the dash with whiteout)..... now you know where your tabs are in relation to the bottom of the boat.
For me.......to smooth the ride in the rough I generally trim in as opposed to using alot of tab ....... I keep the tabs neutral or slightly more......use the tabs to control the pitching side to side.
I agree with gferdon.....Fountains like to run in the rough......people freak out a sometimes when I come out of an inlet or round a point into some rougher water and I speed up rather than slow down
Typically at that point I'll tuck the drives a bit and put the tabs to neutral from my cruising positions......try it for a bit......then speed up if nessesary....doug

bgriff

Thanks for the advice guys!!!! I need some wheel time in order to get used to the concept of speeding up over the ruff stuff. The wife usually is yelling at me to slow down so having her read the replys was helpful.

pullmytrigger

take your time.....when you get to that point and your ripping across the top of some 3 footers (base to crest) and the ride smooths out at 60mph you'll get a smile on your face and appriciate the throughbred your Fountain is...........doug

AMERICAN BAD A$$

My tabs are level with the bottom at about 2.5 on the indicators , I never really go up more than that . When just cruising , I have drives at about 3.5 and tabs at about 3.0 -3.5 , makes for a nice and smooth 50 mph at 3000 rpms .

bgriff

An update on my boat and search for opinions. I brought it in to have the seawater impellers changed and to have a dealer check the boat over and they found that the starboard side prop had been hit and repaired (which I knew) but they say the output shaft is bent and needs to be replaced. Quoted me aproximately $900.00 parts and labor. Does this sound about right?