9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

[andymach23]

I'm thinking of getting a F9.9 Yamaha as a kicker engine for my 20ft boat. I have currently got 5hp 2-stroke kicker and I think it has now died a salty death. I like the idea of the remote flusher on the 9.9.

I've had the 5hp for 10 years and had no use out of it. It just hangs there and just gets warmed up before each trip.

I'm thinking that the 9.9 might be a good idea as I might actually be able to get some decent use out of this motor, as it I could use it to slowly cruise on the river and sip fuel. My main engine is a Yam F80. Alot of the time I drive the 80 real easy and am getting issues with 'making oil'.

If I get a manual start, tiller control and keep the motor on a lifting bracket, will I be able to drop the bracket and fix the engine in the straight ahead position and get decent steerage with 80 hp main engine? The F80 would then just be acting as a rudder.

The follow up questions I suppose are.. does the 9.9 have a friction screw to fix the motor in the straight ahead position and can you fix the throttle at a setting to cruise along?

Any other general comments on this setup?

Cheers

Andy

 

[tashasdaddy]

Re: 9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

you have a lot of weight difference, to mount to one side of the boat. i think steering would be minimal, you need a steering link to main motor, and use the wheel.

 

[SundayMoney]

Re: 9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

The 9.9 is too much. An 8 will be plenty.

I do exactly what you're thinking with my boat. I set the kicker to run straight and steer with the 150. Unless its windy,it works great.

The 8hp will push my 20' boat at over 7mph.

 

[ondarvr]

Re: 9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

Get a T8 you'll love it, as for steering, using the big motor sort of works and it also depends on the hull design and other things, but get a steering link and you'll be fine.

 

[andymach23]

Re: 9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

Thanks guys,

The T8 sounds good. Is the engine reving much to push the boat at 7mph?
My boat weighs about 2800lbs including engine and gear.

Also, would it be an option to just get the normal F8 and get a high thrust prop for it? I maybe don't need all the bells and whistles of the T model.

One more question please. If say I got the manual engine, is it possible to fit remote controls down the line?

Cheers

Andy

 

[ondarvr]

Re: 9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

If propped correctly, the motor should be turning max RPM at 7MPH if that's all the faster it will go. At displacement speeds 1/2 throttle may be 5MPH, 3/4 may be 6MPH and WOT could be 7MPH.

An F8 will work, just not as well, even with a high thrust prop it won't have the same thrust as a T8.

Converting can be done on most small motors, but can be costly depending on the model and I'm just talking about controls, not electric start.

 

[gss036]

Re: 9.9 Yamaha 4-Stroke as Kicker on 20 ft Boat

The T8 and T9.9 are basically the same engine, just different carbing. I just got a T9.9 and got it broke in, I use it on a 23WA and works great. I had a 15 HP Honda previously and they both push the boat about the same. Your hull displacement speed is what will control your speed. If you need the 7 MPH, then go to the T9.9, but don't think it would matter.