I cant reach Max Rpm.celebrity 200

[yilser]

Hello. I have 1997 celebrity 200 boat with mercruiser 5.7 260 hp. I can see max 3600 3800 Rpm and 28 30 knots but My engine max Rpm 4600 4800. Engine full serviced Last week but no any a changing. My service told me that My propeller pitch hıgher and must change propeller more low pitch because My boat is runnıng planne very late abt 8 - 10 seconds. We cant see propeller pitch or any info on My propeller but it can be 19 pitch. Any body have info abt 1997 model celebrity orjinal propeller dimansions? What can ı do for reach 4500 4600 Rpm with my engine. Please help

 

[Sportster-2001-951C-Stock]

You really must talk to a prop shop to confirm the correct prop (14"dia X 19"pitch should be about right I think). You'll need to know the engine HP rating, weight of boat and they may ask the stern drive gear ratio just to confirm it's correct. Gather your info, they'll need it

Even so, it might be necessary to try a couple sizes to get it perfect but with ALL the info most shops will hit it 1st time.

Anyway, I would try to shoot for the top spec of 4800 RPM if possible, but in any case don't exceed 5,000 RPM That should get you between 45~48 MPH, I expect. More weight means less speed of course, and longer plane time, which can necessitate a smaller wheel to get on plane in a reasonable time.

Is the prop stainless or aluminum? Aluminum is safer for your boat in case you hit something submerged, the soft aluminum lessens the chance of shock damage to the stern drive (Alpha drives are pretty tough but in my lake there are shallow areas)

A stainless prop has thinner blades, thus has somewhat better performance.

Diameter AND pitch are two metrics to consider, engine HP, weight and length and gear ratio.

But you're ~1,000 RPM shy of optimum which means to me the boat might have a problem, is heavily loaded. or your propeller is a large diameter?

Here's a prop chart but again, gather your specific info (Serial # of drive and engine serial # are often enough) and call a prop shop before buying something!

Sometimes used props can be re-pitched

http://www.go2marine.com/go2_structure/mfr/michiganwheel/mercruisersd.shtml

 

[yilser]

You really must talk to a prop shop to confirm the correct prop (14"dia X 19"pitch should be about right I think). You'll need to know the engine HP rating, weight of boat and they may ask the stern drive gear ratio just to confirm it's correct. Gather your info, they'll need it

Even so, it might be necessary to try a couple sizes to get it perfect but with ALL the info most shops will hit it 1st time.

Anyway, I would try to shoot for the top spec of 4800 RPM if possible, but in any case don't exceed 5,000 RPM That should get you between 45~48 MPH, I expect. More weight means less speed of course, and longer plane time, which can necessitate a smaller wheel to get on plane in a reasonable time.

Is the prop stainless or aluminum? Aluminum is safer for your boat in case you hit something submerged, the soft aluminum lessens the chance of shock damage to the stern drive (Alpha drives are pretty tough but in my lake there are shallow areas)

A stainless prop has thinner blades, thus has somewhat better performance.

Diameter AND pitch are two metrics to consider, engine HP, weight and length and gear ratio.

But you're ~1,000 RPM shy of optimum which means to me the boat might have a problem, is heavily loaded. or your propeller is a large diameter?

Here's a prop chart but again, gather your specific info (Serial # of drive and engine serial # are often enough) and call a prop shop before buying something!

Sometimes used props can be re-pitched

http://www.go2marine.com/go2_structure/mfr/michiganwheel/mercruisersd.shtml

My propeller is aluminyum and no any weigth. Just I in boat. I wıll contact mercury main service for prop.