[Mike S]

So my boat is finaly up and running and have enough break in time on the new 7.4 in it. It has the 330 Hp f.i motor with the bravo 1 with a mirage 21p stainless on it. Its the prop it came with when I bought the boat last july. Well now that all the issues are worked out with the boat. I've been trying to get my prop situation figured out. Two of the blades have a few knicks in them. Being only a 21 foot small bowride with a big ole' motor what do you think I should be seeing topend wise? I would think 55-60 but it just doesn't seem it. My speedo and tach are at fariah now getting fixed and I'm kinda stumped. The boat gets up on plane pretty good nothing lightning fast and once up cruise's. Do you think a 21 pitch could be too much for the boat, Hurting my topend? I was thinking about maybe trying a 19 pitch 4 blade stainless to see how it goes. Kinda hoping someone with a setup like my shabah 210 can lend some insite on where to go

[Z 202]

I would suspect you'd see close to 60 with that big block in a 21' bowrider. GPS is the only way to accurately evaluate your speed.

The 21 p that came with the boat is probably a good match. 19 might improve your hole shot, but you should have plenty of hp to get up on plane.

If your WOT rpm in in the zone 4400-4800 you're probably propped just right. If you know the numbers (speed WOT and drive ratio) mercury's prop selector should give you an idea of what you might run.

[mikeyt]

If you drop your pitch from 21" to 19" you will likely lose some of your top end but gain some hole shot & low end punch. I think this is a good spot for a 21" $tainle$$ HIGH 5 prop but the Mirage should do a good job.

[jsk9675]

I have a 1997 Talari 209 Mercruiser 5.7LX Alpha 1 need to replace the prop and am not sure of what pitch and diameter I should be using


thanks
john

[dwmax]

I have a 350 mag mpi with a alpha 1 and a 23pitch high five prop and I see 56mph with 6 people and 60mph with 3 people depending on weight. With having a big block 454 and a bravo 1 you should see atleast 58-60mph. Getting the right prop can be very tricky so before you spend alot of money on a new prop, I would see if there is a shop around you with used props that might let you try out a couple of different props until you find the right one. good luck

[rooperdan]

Hey Mike, I have a 1998 Shabah 210 with a built 350. At WOT i run about 4900 rpm with a 21P 4 blade Mercury Revolution SS prop . I also spent alot of time checking out wich prop works best for this set-up and foud this to be the best . I run 60 mph at 4800-4900 rpm at WOT but spend most of my time crusing at 40 mph . Hole- shot i'm up and at plane in 3-4 seconds

[mikeyt]

Originally Posted by rooperdan

Hey Mike, I have a 1998 Shabah 210 with a built 350. At WOT i run about 4900 rpm with a 21P 4 blade Mercury Revolution SS prop . I also spent alot of time checking out wich prop works best for this set-up and foud this to be the best . I run 60 mph at 4800-4900 rpm at WOT but spend most of my time crusing at 40 mph . Hole- shot i'm up and at plane in 3-4 seconds

About as close to perfect as you can get.