newbie that is very disappointed, any advise???

[ss3964spd]

Casey,

You've cleared it up for me. If the drive is in gear and the flywheel (balancer?) turns when you turn the prop I doubt the coupler is the issue. It's possible, but not likely in my mind. Ditto on the prop.

If either of those were bad you'd see the RPM's go up without a corresponding increase in boat speed. Rather like a badly slipping clutch in a car.

I presume that the drive is all the way down when you are running the boat on the water. At this point I'm with Glenn - the boat is under propped.

Dan

[cashone05]

So should i put the stock 19 3 blade on it and see what happens?

[ss3964spd]

I'd certainly start with that Casey.

[mcoffey]

Yep, me too. 19p is always a good start point for most. You can guage RPM from there and if too low, go to 17 and if too high, go to 21. 19p normally gives decent hole shot and decent top end as well so would be good as reference compared to what you see with current 5 blade.

[cashone05]

Well i finally got the smart tabs put on and switched to a 19 pitch aluminum 3 blade prop. It was night and day difference. The boat comes up on plane relatively fast even when i had four adults on the back bench and only one in the bow. And i do not hit the rev limiter now. The rpm's toped out at about 4700 at 43 mph. I think im happy with this. Is there anything i should do to make it better or just leave it alone?

[seapuppy]

sounds like you hit the numbers....right at the end of the rev limit and hitting 43mph with 4 adults....that ain't fast enough????



SP

[cashone05]

its quick enough and it was actually with six adults. I was just wondering if i finally got it right. Thanks for all the input.

[seapuppy]

sounds like it too me......


SP

[JoDo]

This was a great thread to read through. I'm a new boater and enjoyed seeing Casey work through this and end up feeling much better about his boat. Looks like a good group here.

[pascavone]

glad the prob solved it, I always wonder why it was changed to being with.....?

[mcoffey]

I think you got it right now. With only 2 adults you will probably get 47-48 out of it which is not that bad. Now you have a good baseline though and can experiment with props if you want to tweak it a bit. If you go 3 blade stainless, you might get another 1-2 mph out of it and slightly faster holeshot as it will not flex as much as aluminum. Maybe a 4 or 5 blade version would perform better than the 19p 3 blade. They say when going from 3 to 4, decrease pitch by 1 so that would mean an 18p 4 blade should give similar performance to 3 blade 19p (though maybe better holeshot and higher top end?).

Good luck and let us know if you do play and decide something else, it could help us all.

[cashone05]

with this theory my five blade 17 should have worked right??

Originally Posted by mcoffey

I think you got it right now. With only 2 adults you will probably get 47-48 out of it which is not that bad. Now you have a good baseline though and can experiment with props if you want to tweak it a bit. If you go 3 blade stainless, you might get another 1-2 mph out of it and slightly faster holeshot as it will not flex as much as aluminum. Maybe a 4 or 5 blade version would perform better than the 19p 3 blade. They say when going from 3 to 4, decrease pitch by 1 so that would mean an 18p 4 blade should give similar performance to 3 blade 19p (though maybe better holeshot and higher top end?).

Good luck and let us know if you do play and decide something else, it could help us all.

[mcoffey]

In theory, sure
Sorry but I have no experience with 4 or 5 blade props. I have always run nad been happy with 3 blade. I did read somewhere else where each blade should only lower RPM by 50-100. So going from 3 blade to 5 blade yet staying with 19P, you should only loose 100-200 RPM. Not sure it that is enough to warrant switching from 19 to 17.

Now it also could be what others had suggested with just "blowing it out". Never had that happen so not sure what that is like or what causes it.
Could also be a spun hub which was mentioned earlier too. Did you ever mark the outside ring of prop and inside part of hub and take it for a spin to see if tehy still lined up after?

I do hear mention of a lot of people running 21P high fives with good success so maybe we are looking the wrong way on pitch? Everything you see out there says decrease pitch for extra blades. But at the same time, extra blades grab better so adding an extra blade and going down 1 size is giving you the double dose of holeshot power. So it would stand to reason increasing pitch would offset adding extra blades and give you the best of both, good holeshot with good top end. But I guess the real key here is to keep RPM at WOT where they should be and maybe that is why they say to lower?

Anyone else run 4 or 5 blade props and can offer some sound advice here?

[RoyR]

I run a 14.5"x19" AL prop on my 1900SR, and it performs great!!! Was thinking about switching to SS or 4-blade, but for the cost and not knowing how it will perform, decided not too.

Mercury Marine Black Max 3-blade Aluminum, #48 832830A45 19P

http://www.wholesalemarine.com/p/48-832830A45/

[CountryME]

Roy, what year 1900 do you have. I really like that depth sounder, is is aftermarket or stock?

-JP

[cashone05]

Im not sure what boat roy has but mine is a 2005 and it has that depth finder and its stock

[RoyR]

Sorry, don't log in that often....it's a 2002.

Originally Posted by CountryME

Roy, what year 1900 do you have. I really like that depth sounder, is is aftermarket or stock?

-JP