Single Yamaha T9.9 powerful enough for Tangaroa?

[Allen Bosely]

 Would a single Yamaha T9.9 High Thrust be big enough for a Tangaroa fully laden?

 Not for maneuvering in tight places where two engines would be helpful for tight turns and such, but for general pushing the boat along.

 The Yamaha T25 High Thrust weighs almost twice as much (T9.9 110lbs vs  T25 201lbs) as the T9.9. The weight isn't so much about the boat carrying the extra 90lbs or so, but for mounting and dismounting the for maintenance and storage off the boat for security.

 From what I understand the Yamaha T9.9 is a pretty strong motor for low speed displacement type boats and not really comparable to the usual 9.9 hp motors.

 It would be nice to be able to compare the thrust between the Yamaha T9.9, T25 and other brands of current motors in the same power range. Even though it probably wouldn't be an exact measurement type of comparison.

 The longest shaft that the Yamaha T25 comes in is 20" but there is a 5" shaft extension available, the T9.9 is available with a 25" shaft from factory. so shaft length isn't a deciding factor necessarily.

Anyone use a Yamaha T9.9 on a Tiki 38? If so how does it perform? I mow the T38 is a bit bigger and definitely heavier. But if a single T9.9 works well on a T38 it would work even better on a Tangaroa.

Cheers, Allen

 

 

[Andy Best-Dunkley]

Yes, I agree there! I admire the "purist" ideal, but here in Finland there would be no reasonable way to have a cat the size of a Pahi 42 without decent motors. Routes through the archipeligo can twist and turn through 90 or even 180 degrees sometimes, not to mention the wind direction!! This summer we turned a corner round an island, having the wind behind us. Expected to continue to have a nice downwind run when the wind hit us in the face ;-) Would love to visit your part of the woods sometime Allen! Enjoy your seas!

[Mike Haromy]

funny you just asked that.  i have the tiki 46 and was torn on what to get.  i was looking at the tohatsu 20 hp long shaft with the 5" extension but it's really a motor to get a very light boat up to 20 kts quickly where the T9.9 is the range of a sailboat with a huge prop and low gearing.   I decided to go with one of each.  If you wait for a week for me to finish the breakin i'll let you know how fast a fully loaded tiki 46 will go with just the T9.9.   Even at half throttle it moves and stops the boat immediately compared to the two old 2 stroke motors i was using temporarily.

[Allen Bosely]

Mike, that would be great! I think it would be a help for others also to have a real world test on a boat as big as the T46.

I think that with only Yamaha offering a line of high thrust outboards and lighter, faster type boats much more common than slow displacement boats that there isn't much real world experience to compare with.

I think the low geared, I mean really low compared to most outboards 2.08-2.17:1 compared to the T9.9 at 2.98:1 and the big prop it can swing really can make a difference in power/thrust for our kind of boats.

Your input with direct comparison between the Tohatsu & Yamaha will be most valuable and helpful.

Certainly looking forward to it! :-)

Cheers, Allen

[Mike Haromy]

So after a break in,  at full throttle, no masts, weighing 13-14000 lbs we did 4.5 kts on just the yamaha 9.9 without lifting the other motor out of the water.  

[Allen Bosely]

Wow thanks Mike. Thatʻs pretty good performance from a 9.9 hp! 

As a side note I decided to go ahead and build the Narai Mk IV instead of the Tangaroa. I have the plans and the Narai is what really what makes my heart go pitter patter! lol

Should be able to start building sometime in Dec.

All I really need/want from a motor is to be able to maneuver her some (not in confined areas, no marinas here really) and be able to make it into the bay if the wind dies down just as coming in. If the wind is blowing enough the give the 9.9 problems, weʻll sail in! :-)

A hui hou, Allen 

[Bill Ludeman]

I can directly  address this. I own a Tangaroa mk1 that has had several of these yamaha 9.9 high thrust outboards. The original builder supplied two extras when I purchased the boat plus the one that was on it.    I bought my boat in Annapolis Maryland and brought her down the Chesapeake and the intracoastal to Palatka Fl.  In the course of that trip I exceeded 11 mph several times under this power alone.   By GPS.  One engine full throttle.  I tended to run it wide open and it did not seem to care.   In extremely rough weather against strong headwinds my speed was cut to 3.5 mph but in those conditions the boat was hobby horsing terribly and I had no desire to push it faster.   Several times I was in rough enough conditions that we cut our speed to 4 or so mph voluntarily.     Typical cruising speed in "normal" conditions was 7.5mph.   Typical fuel mileage varied between 8 mpg and 10 mpg.   Carefully documented in my log.   Also please note that I am sure I was overloaded and suspect the entire rig weighed about 7000 on this cruise.

Now for another look at this.   I have moved this boat several times against wind and waves with a 2 hp nissan/yamaha 2 stroke and my 12 ft portaboat which I use as dinghy.  The two hp will scoot the tangaroa along just fine in a calm condition and WILL move it against a even a serious headwind.   That is an empty boat.    The most recent trip was extreme.  Hurricane Mathew broke my mast which came down and broke the crossbeams turning my hulls on their sides and dropping the broken mast and beams in the water under the hulls.   I towed this mess across the harbor over a 1/4 mile against 10-15 mph headwinds in a chop with that same two hp dink.   It was extremely slow.  But the 2 hp did do the job.  It has a tiny little prop and it just chewed along barely moving.   It was all I had and I had to get the wreck out of the water.

By the way the entire boat and wreckage are now at home on my acre and I am sorting out what to do with it.  I had tried to sell it but had zero real interest.  At this point I am glad to still own it.  Love my Tangaroa. 

Please consider your own tidal runs, currents and wind conditions but I am certain that a 9.9 Yamaha High thrust in good condition is a good match for a tangaroa size boat.   Bill Ludeman  SV Tang.

[boatsmith]

wow Bill! That does suck! real sorry to hear that.