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 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



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Hi Allen

I've got 2x9.9Yamahas on my T38. I mostly motor with just one motor. Boat speed is generally around 4 knots and its perfect for this in calm conditions I can go a lot faster but its way more fuel efficient around this speed especially if I have to cover some miles.. As soon as there is a decent headwind, you really feel it and I use the other one as well. If I  was just going to have one motor on your boat, I might look into the 15 yamaha with the high thrust prop. I love my two motors and its so good having a back up should one play up for any reason.

Hope this helps

So if there is a head wind and maybe some current, the single T9.9 wouldn't be able to maintain 4 knots or so even with the throttle at 75% or so?

The T (High Thrust) T9.9 & T25 have lower gearing in addition to the bigger High Thrust props.

Do you have T9.9 (High Thrust) or F9.9 (portable) motors?

Cheers, Allen

Thats right, the speed drops right down even at full revs, but we're talking 25 to 30 plus knots here. In Fact if the wind is this strong I will use the two motors as a saftey thing.

Not sure which ones I have. I know they have the high thrust props and the lower gearing. Will have a look tomorrow.

High Allan,

I have on my Pahi 42 to Yam 9.9 ft.

With one Motor (normaly) I reach 5 to 6 knots

Both together are 10 Knots (throttle 75%) in fair condition.

Consumption each 3 liters per hour.

Sailing greetings Wolfgang

We also have two Yamaha 9.9 high thrust motors on our Pahi 42. If you EVER want to go into a small harbour or marina I would seriously recommend fitting twin motors!! When I first got the boat 10 years ago she had one Tohatsu 18hp mounted centrally. It was fine for motoring in calm weather, but it was hard going against a strong headwind, basically you had to wait or find another route. Turning circle was BIG, which is interesting when messing about with monos when trying to get into a marina ;-) !! With two motors you always have a back-up, peace of mind, and turning ability, which for where we sail is a must.

 It will be an coastal/inter island cruiser in the Hawaiian Islands, I live on the Big Island. Here on the Big Island there aren't any marinas that I would ever go into as there are only a couple marinas and they for boats slipped there and not sure a wide Tangaroa would fit very well anyway.

We have bays, lagoons & coves here with few to no other boats in or close. I would like to not even have a motor but I know realistically a motor will be helpful and a safety to have. 

If I were in an place that had smallish harbors, marinas & rivers, then would go ahead and have two motors for maneuverability and redundancy. But for the foreseeable future a single motor of sufficient power to motor along at 4-4.5 knots in moderate conditions would be preferable.

With that said, wold a Yamaha T9.9 High Thrust be sufficient to get 4-4.5 knots in moderate to mild condition on a Tangaroa? The Tangaroa Mk 4 will be stretched 2'-6" and 22'-6" beam (with Hanneke's blessing) so basically the same length and width as the Tiki 38 but lighter. The Tangaroa will be a good bit lighter at around 8000 lbs max compared to the T38 at 11,000 lbs listed max.

I appreciate all the input guys.

Cheers, Allen   

ok. I think if you are only having one motor, bigger than the 9.9 would be my personal choice.

That's what I was wondering. If the T9.9 would be marginal, I would rather go up to the next size to the T25 and not have to struggle with one a bit on smaller than what;s really needed.

The difference in weight isn't enough to be worth the potential issues of being underpowered and wishing had more power.

With the T25, there would be plenty of power to get away from rocky shore if needed and can be ran a low throttle for most uses. Be easier on engine not being pushed hard most any time it's being used.

Cheers, Allen


I ended up taking the two 9.9 yamahas off my tangaroa.. I just run a 4hp Yamaha if there is no wind.. the rest of the time I sail.. that's what a sailboat is for.. without pods, fuel, motors the boat is over 250kg lighter and sails so much better. I also save ,apart from fuel costs, about $400 a year in registration and because it is classed as a non registerable vessel  the water police / inspectors tend to leave me alone as I now don't have to comply with all of their regulations. In flat water I get 3 knots out of the 4hp..and if there is a breeze I sail...  I have to be a bit more mindful of where I anchor as I almost always sail on and off anchor I do not miss the noisy smelly things at all. Visits to marinas are general not on the agenda but in tight spaces , where there is a will there is a way. I understand that some people may be more comfortable with a couple of big motors.. but without, you certainly learn how to sail your boat..

Steve, that's good food for thought.

I don't want to get in a position that I Have to use/depend on the engine to keep me off the rocks or some other situation. The engine might not start or if it's running might 'hiccup' and then I'm in a really bad situation. 

Really prefer to use sails instead of counting on a motor. If a Yamaha T9.9 can move a Tangaroa around that's all I need. It would be used to motor a short distance when diving (free diving) spear fishing maybe motor out of a bay before raising sails with inexperienced people with me, give em time to get sails hoisted and going without having rush kind of thing.

I'm not quite a purest, but want to be as close to one as I can be! Lol If the wind dies down and cant get back into bay, will just go a ways offshore and heave to with sea anchor or get close enough to drop anchor and sail in later or the next day. Will have everything i need to stay onboard for however long I like pretty much. :-)

Not concerned or interested in motor sailing, if there's no wind as long as I'm not drifting into rocks, which I will always be sure not to put myself into that situation, I'll just hang out onboard till the picks up again. That's part of the charm and fun for me. 

So the 4 hp can move your Tangaroa around some as needed then? 


yes ,the 4hp is mainly there for 'emergency' use such the wind dropping right off and a current taking me where I don't want to go.. I find that planning a trip without an end time is very important.. mostly the shit hits the fan when there is a deadline to adhere to and you've pushed to be in a place where it is not wise to be.. a couple of motors will generally pull you out but I've learned to not put myself there in the first place and if you and if you have to motor upwind in 20+ knots you gotta ask yourself .. how did it get to this , should I have done things differently...

Hi Allen

I guess you buy the gear for you boat that suits the area you sail in and the type of cruising/voyaging/daysailing you do. Also the type of weather you get.

In New Zealand the weather can be changeable at times and on occasion catch you out, so we need to be prepared for all sorts.

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