help me choose a dink motor

RWS · Post by **RWS** » Thu Nov 15, 2012 6:00 am

RIP 1976 Mercury 9.8 110 Series at 65 lbs

She starts consistently on the second pull, but is simply not worth putting any serious money into a lower unit on a 1976 Merc

Speed is fun on our 10.5' hard air floor dink with inflatable keel.

We use a St Croix mini crane to safely load the dink engine from the lazarette to the dink.

So, Yamaha 2 stroke 8 HP at 60 lbs

or

Yamaha 2 stroke 9.9 HP at 80 lbs

(I can change the reed valve plate on the 9.9 to get 15 horse....

But an 80 lb dinghy engine.........

even with the mini crane, seems like a lot of weight to heft around.

Your comments are appreciated!

RWS

prowlersfish · Post by **prowlersfish** » Thu Nov 15, 2012 7:04 am

That is a tough choice . I have a 8.0 @56 lbs and a 9.9 @86 both nissans I also have crane to lift it . But you still have to man hadle them some what . And the 8.0 is much easier to work with . however its just slighty underpowered for my needs . the 9.9 has plenty of power more then I need and even more when I changed it to 15hp with a kit .

Thats why I have both . what I really want is a nissan 9.8 (56 lbs )

What I would do in your case is beg, borrow( not steel a 8.0 hp and try it to see if it will meet what your needs/whants are with your inflatable fully loaded as you use it . only you can make that judgement not me or any one else .

RWS · Post by **RWS** » Thu Nov 15, 2012 8:35 am

The St Croix mini crane makes it easier to heft over the transom and onto the dink, but 20 lbs of bulk is still 20 lbs of bulk.

If I knew for sure I could pull a tow toy on plane with the 15 I would do so, however we were unable to do that with the Merc built to 12 HP.

So is it 8HP on the dink at 60 lbs, or an extra 2 HP (or 7 if I do the rnew reed valve plate) with an extra 20 lbs hanging off that transom?

Will I cuss the 80 lbs or cuss the 8 HP ?

RWS

jddens · Post by **jddens** » Thu Nov 15, 2012 9:53 am

What is the HP rating on the dink? I would look for something close to that. I bought a 15hp rude, I was originally looking for a 9.9 until I found out they weight the same. Probably more HP than I need but you don't have to use it all.......right?........

. John

RWS · Post by **RWS** » Thu Nov 15, 2012 10:36 am

The dink is rated for 10 HP

That said, I am not an irresposnible operator and the actual 9.9 Yamaha would maintain the same cowling - a sleeper if you will.

As far as the power is concerned - the answer is easy

The real question is do I really want 80 pounds hanging off the back of the dink and do I really want to have to deal with alll that heft..... even with the mini crane I still have to man handle it into and out ofd the lazarette plus handling it on the mini crane.......

RWS

prowlersfish · Post by **prowlersfish** » Thu Nov 15, 2012 1:16 pm

I do find the 86 lbs of my bigger eng a real pain for me even with the Crane . most the time I use my 8 hp . Now if I going to somewhere where I will be a few days and use the dink I will take the larger engine . but its not worth it for just weekend IMO .

RWS · Post by **RWS** » Thu Nov 15, 2012 4:21 pm

Must be 2 stroke. - period.

If I stay with the Yamaha - which is now my preference, it's either the

8 HP at 60 LBS

or the

9.9 HP at 80 LBS

The price is essentially the same

The Merc was 64 lbs

'Course ten years from now when I am an even older fart, I'll be wishing I had a 2 HP Honda air cooled motor !!!

RWS

vabeach1234 · Post by **vabeach1234** » Thu Nov 15, 2012 4:44 pm

Something to consider:

Pre 1986 outboards were rated at the powerhead.

Post 1986 they started rating them at the prop.

You lose some power from the powerhead to the prop, so your old 1976 9.8HP might have been closer to a current year 8 HP.

TBone · Post by **TBone** » Thu Nov 15, 2012 6:52 pm

if you were closer, you Could get my 01 Merc 15 2 stroke for $950, and Ill give you the Caribe inflatable and trailer to go with it.

prowlersfish · Post by **prowlersfish** » Thu Nov 15, 2012 7:44 pm

vabeach1234 wrote:Something to consider:

Pre 1986 outboards were rated at the powerhead.

Post 1986 they started rating them at the prop.

You lose some power from the powerhead to the prop, so your old 1976 9.8HP might have been closer to a current year 8 HP.

Good point . Gut feeling is that the 8 hp yamaha will do the job

RWS · Post by **RWS** » Thu Nov 15, 2012 8:12 pm

prowlersfish wrote:
vabeach1234 wrote:Something to consider:

Pre 1986 outboards were rated at the powerhead.

Post 1986 they started rating them at the prop.

You lose some power from the powerhead to the prop, so your old 1976 9.8HP might have been closer to a current year 8 HP.
Good point . Gut feeling is that the 8 hp yamaha will do the job

=============================================

This would apply if my 9.8 Merc was 9.8

However it was built by a retired Merc instructor with jets and reed valves to 12 HP

Also, electronic ignition

So maybe these two will be equal?

12 at the head (Merc) vs 9.9 at the prop (Yamaha)

RWS

prowlersfish · Post by **prowlersfish** » Thu Nov 15, 2012 10:20 pm

Then again Maybe just doing the job is not enough . (enough fun )

RWS · Post by **RWS** » Thu Nov 15, 2012 10:39 pm

On closer inspection the two 8 HP Yamahas are in far better shape than the 9.9

These videos helped me get back to the 8 HP

http://www.youtube.com/watch?v=AlLFjNFixyQ

http://www.youtube.com/watch?v=XQ_6LX63dkU

http://www.youtube.com/watch?v=Zjhc4T7kExw

the last one shows 17 MPH with 2 people on board

the 8 is soiunding better and better now.

RWS