Top Speed of 2007 26M

[Scottie]

With a stock 2006 Honda 50 4-stroke motor and ballast tank full what should be the top speed attainable. I was able to get her up to about 12mph with 2 passengers and myself at about 5500rpm. Is there anything that I can do to substantially increase the top speed?

[Carioca]

I had about the same speed with my 50 hp Yamaha with a 12 pitch prop.
I went to a big eared 9 pitch (pontoon) prop and now get 17 mph topped out.

John.

[Boblee]

This is a post from when we tested our props

In heavy sea or with max load including heavy dinghy behind I believe the Hydrus is possibly the best prop but can get over 5000 rpm now on flat water so am reasonably happy to keep it (13") as a spare.
On a recent run the bigger prop was spinning at 5200 rpm but it has a couple of nicks in it
These tests were done with GPS reading and hooked up to the laptop which showed our tacho to be spot on water was a little choppy no current and slight headwind.

Will be contacting the dealer to order the spare prop, the original is a hydrus ---- 11'pitch and the one we tested was 13" pitch.
The hydrus going into a light wind at 5800 rpm WOT was getting 14.3 mph and 15.5 with it, the 13" at 5400 rpm WOT was 18.6 mph and with the wind 19.3 mph.
With ballast in the 13" at 4900 rpm WOT was 15.5 our boat is fairly heavy due to some of my mods and cruising weight will be probably be 150-200 kgs heavier (330-440 lbs).
The 13" prop was a standard evinrude stainless but we will be getting an aluminium one.

[Frank C]

... Is there anything that I can do to substantially increase the top speed?

There is one very quick modification to increase top speed.
Empty the ballast tank.

I only use ballast when sailing. When motoring I generally empty it.
The only exception ... I never change ballast states in rough water. So if ballast happens to be full when I elect to begin motoring, I'll empty it if waters are flat, otherwise, leave it as-is.

[NiceAft]

What Frank said about the ballast is correct, but you must take into consideration where you are. I do most of my boating on a busy, large city river. I empty the ballast only occasionally because of the need to make sudden turns (flotsam, quiet tugs sneaking up on you, jitterbugs on their PWC's, boaters who only know to go fast and to heck with everyone else, etc). If you have plenty of room to make graceful course corrections and turns, or if you are not going fast, fine. If you boat on a congested, narrow river, watch out.

One of our fellow members hit a log this weekend and broke a rudder. I would not wish to have to make a quick turn without the ballast being full.

One other thing. Either the ballast is full or empty. There is no in between

Ray

P.S. I tested my fully loaded boat yesterday at 6000 rpm and the speed was 15 mph according to the GPS. I have a 50hp Honda 4 stroke. 6000 is the redline. I just wanted to see what it did. At 4800 rpm,s (most efficient engine speed) I did 10mph.

[Boblee]

Mainly have an empty ballast when motoring but as Ray said in a river where you need control and the wind cuts up you are better with it in and especially if you can't use any boards because of submerged logs etc especially at low speeds.
If you can get on plane with ballast in it doesn't cut your speed back as much but if the waters a bit choppy or you are really loaded you will need to dump it to get on the plane.

[Scottie]

Thanks guys. I am just getting acquainted with the boat. I have only been out a couple of times. I do feel better with the ballast in at this point, but will experiment with it empty. I was curious if this speed is what I should expect with the standard equipment. Another prop sounds like it might be an avenue to explore. I’m always a little leery changing what the engineers have designed.

[Moe]

Another prop sounds like it might be an avenue to explore.

Being able to hit 5,500 rpm with ballast and two persons aboard sounds like it's propped pretty close to where you want it to be.

[tangentair]

Another prop sounds like it might be an avenue to explore.

Being able to hit 5,500 rpm with ballast and two persons aboard sounds like it's propped pretty close to where you want it to be.

I agree also, sounds like your delivering max rpm at the usual loaded state. I think I hit 16 last year ballast empty, I have a 50 merc, but when the winds are out of the west and the lake is like glass (best for speed runs), I want to sail not motor so I seldom run wide open. Any chop and I back it down, way down. The smooth ride alarms sound off very quickly.

[Boblee]

Scottie agree you seem to be propped about right but as for changing what the engineers designed, that will change from boat to boat and your loading and usage levels.

[solentboy]

Yesterday with no winds and a stock 2008 Yamaha 50 (High Thrust) I reached 4700 RPM WOT and 18.6 MPH with no ballast. Does that spound about right ?

What difference do you foind ballast / no ballsat makes ?

[Moe]

No, 4,700 rpm unballasted does not sound right. If you are unable to reach the outboard manufacturer's rated rpm range at full throttle (5,000 - 6,000 rpm), with the heaviest load you will normally carry (including being ballasted), you have a problem. It could be the throttle cable/linkage is not opening the motor's throttle body all the way.

More likely, it is because your prop has too much pitch. This is like driving an automobile uphill in too high of a gear, lugging the engine. You should be able to reach at least 5,000 rpm ballasted and fully loaded. This is what is most important. Ideally, the prop pitch should also not let the engine exceed 6,000 rpm at full throttle when lightly loaded, but if it does, you can back off the throttle a bit.

Rather than estimate how much rpm will drop even further below the recommended rpm range when ballasted and fully loaded, I recommend you find that out for yourself. Also try to find out the pitch of your current prop to have a point from which to work selecting a new one.

[c130king]

Did you try the old "tap on the guage" technique to make sure your RPM guage was not sticking at 4700 RPM?

Your speed sounded pretty good...but your RPMs seemed low.

My Tach will stick sometimes...a couple good raps on the guage will normally free it up.

Jim