50 Yamaha ?

[snapjigger]

Looking for a little insight. I just purchased a 03' 50 Yamaha 4 stroke there are no markings on the prop. The motors on a 1650 rebel tiller. Top speed is 32mph does this seem a little slow? Had a 30 4 stroke on before that would push 30mph just wondering if anyone has a similar rig with an answer..

Thank's Snapjigger

[MIDNIGHT777]

Snapjigger, My Alumacraft Lunker 165 counsel (16.5ft) w/'03Merc 50 4 stroke will only do about 32 give or take depending on wind with just me and all of my equipment. (2 full 6 gal. gas cans, 2 batteries, anchor, ect......). I was told that is about right. If I go to the Alumacraft web site it says that it should do over 40 on the performance tests with a 50hp max. They dont specify 2 or 4 stroke. Also I am sure they run it completely empty. I think with the 4 stroke you give up a little speed.

Matt

[snapjigger]

Thank's the Yamaha HSOforum also says about 33mph with 13" pitch prop. and up to 44mph with a 15" pitch. I just wish I new exactly what size prop I have must be a 13" according to the performance. 44mph would be a little spooky in that light boat anyway..

[nrthwds]

If you pull your prop off the size should be stamped on the backside, I have a 60 Yamaha.

[delmuts]

snap. take your prop off ( it wouldn't hurt to check for line or weeds behind it once in a while any way.) on the end you should see some numbers; such as 12.5X13 or 13X15 . what these numbers mean is the first two are the prop dia. the second two are the props pitch. just incase you didn't know. del

[Surface Tension]

Something doesn't sound right here. You could hit 30 mph with a 30 hp and the same boat wont go over 32 mph with a 50 hp motor?
You need to check your WOT RPMs.
Whats model of your boat?

[snapjigger]

Just found #'s they where inside the hub. It is a 13 pitch. The motor is brand new. It does seem like there is no speed diffrence at wot verses about 3/4 throttle. It's sitting on a Rebel 1650-V 03' What would a higher pitch do to overall performance the dealer said this prop was overall good for holeshot as well as top end.... Thank's again

[mpete54]

I have a '98 1650 V Rebel with a '98 40hp Merc 2 stroke and I can get about 31-32 mph with 2 guys and gear with a 13 pitch prop. We just bought a 12 pitch prop from a prop place down in the cities and the guy there told us that a 12 pitch would move us a little bit faster. Now, I know absolutely nothing about propellers but I guess the guy said that it has to do with the RPM's at WOT? Doesn't power tilt and trim have something to do with the speed too (such as being able to get the boat on a better plane?)? I thought that I had heard somewhere that 50 hp motors were built more for fishing boats, thus sacrificing top end speed for the ability to troll down better. Any truth to that?

Matt

[snapjigger]

Not sure about that? I don't have a tach so not sure what rpm I'm running. 32mph is fast enough in that light of a boat but would be nice to maxamize my performance. That was the main reason I jumped up to the 50 was not a cheap move...

[CHESSY_NUT]

Snap- My 16' Starcraft pikemaster - 50HP 2 stroke yamaha running wot with 13 pitch prop does 33 mph and 5500 rpm with boat loaded down. With 15 pitch prop same set up would only pull 5000 rpm,also would not get on plane as fast.I must say it ran faster with just me in the boat but overall performance was best with 13 pitch.

[Trailblazin]

I run a Evinrude 40 horse 4 stroke with a 16ft Crestliner. I ran a 12 inch prop the first year and only got to 30 mph. The prop was classified as "Standard Prop".
After sopme research and talking to many folks, I learned that to gain speed, I need to go up a pitch or 2 and that would also lower my RPM's.

I went to a 15 pitch, or a "Speed Prop" and I gained 5mph and now I am running 35mph!

When the kids want to go tubing or skiing, I put the stanadard prop on because I get better hole shot. When I am solely fishing which is 90% of the time, my Speed Prop gets me where I need to go and the performance is much better.

Check out this site for more info!

Trailblazin, sorry no unauthorized links.

[This message has been edited by Surface Tension (edited 04-20-2004).]

[ChuckN]

I once had a older 16' Lund Stinger with a 40hp Johnson and all I could get was 29mph GPS with a high pitch prop. These boats aren't meant for speed. I think the speed for your boats are in the ballpark.

If you go to a higher pitch prop I would bet you will definitely find it hard to get on plane and run lower recommended RPM's at WOT.

[Fishing Junky]

Snap. A tach would help greatly in answering your question. Also, drop your motor all the way down and check the cavitation plate. Run a straight edge from the bottom of your boat outwards. Your cavitation plate should be even with the bottom of the boat or slightly above for better performance. Most dealers just throw the motor on the transom and bolt her up. I've raised a few motors and found it raises rpm's a little and gets the boat on plane faster. Thus allowing to go to a higher pitch prop, resulting in more top end. Hope this helps, Junky........

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A fishing guide is just a fishing junky who takes others with him to support his habit.

[This message has been edited by Fishing Junky (edited 04-20-2004).]

[Trailblazin]

Agree on the last post too....
Read the manual and see where your RPM's need to be. The lower pitch prop has me running 100-200 RPM's over the rceommended, which is 5800. The higher pitch prop or speed prop, put me @ 5700-5800- @ WOT and I gained 5mph's....My getting on plane was minimal - 2-3 seconds was all. That was not my concern - my concern was the RPM issue, top end speed, and performance.

[Surface Tension]

Fishing Junky has given you some good advice. Check the RPMs at WOT and the motor height.

[snapjigger]

Wow lot's of advise. That's why I like this site. Someone always has an answer. I will check into the suggestions. I know a tach would be nice but dont have one as of the moment. The motor is mounted up on 2nd hole so I'm assuming it's right but I will check anyway. I had it put on at Rapid sports so I assume they did it right??? Thanks again I will let you know what I find out. Scott

[Fishing Junky]

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