17 Aquasport - Power and scuppers Questions

[mgammel]

Hi.  This is my first post.  Just rigged and got my 17 1987 Aquasport in the water for the first time.  Need a little help... Powered her with a 115 2 stroke yamaha, could not find a 90 2 stroke.  Was a little concerned about the weight.  On first run, the scuppers were out of control.  Could not believe how much water came in.  (I do not have the ping pong balls yet).  Secondly, I'm running a 17 pitch 13.25" prop.  Planned nicely and top end was great.  However the nose pointing with one person was very scary.  Felt like she was at a 60 degree angle while getting her out the gate.  With another person in the front is was not an issue.  Any direction or help would be appreciated.  Am I overpowered or maybe a different pitch is needed.  Thx!

Mike - Wilmington, NC

[RickK]

Hi Mike and welcome aboard. 

What year is the boat?  The older ones were ideal with small motors on them - weight was less and the boats remained self-bailing.  You may have to put ping-pong ball scuppers on her.  I thought the 90 and 115 Yammys were the same head, just carb changes?  The newer models should be able to handle the weight of a larger motor.

[mgammel]

Rick- the boat is a 1987.  the 115 yammy 2 stroke is the larger head vs the 90.  100lb diff on the 115.

[CLM65]

Are your scuppers above water when the boat is at rest?  If so, I would go with the ping pong balls.  If not, may be too much weight on the transom.  As far as pitch, is your WOT rpm where it is supposed to be?  If so, see if you can shift any weight forward, or consider getting trim tabs.

[RickK]

I was thinking the Yammys were like the OMC - I learned something today.
As Craig said, shift weight forward if possible, make sure your engine is all the way trimmed down when you take off and if that isn't enough maybe trim tabs are the answer.  You can get those spring activated ones that are always working OR you can just learn to like the hole shot when you're by yourself  - it only takes 2-3 secs to plane off.

[mgammel]

Do you think a Dolphin Tail would work instead of tabs?.   gauges were originally on a 4 stroke.  I forgot to make switch on rpm's back to a 2 stroke.  I'll get rpm at WOT on Sunday or Monday when I try again.....

[RickK]

A doelfin is more for giving you a lower planing speed and lifting the aft of the boat once on plane.
I've had a doelfin and a bob's stabilizer plate and took them both off - actually lost about 3 mph with the Bob's stabilizer plate. Don't remember mph with the doelfin.
On a 170 it should jump out of the water and yes they can raise the front quite high if you jump on it, sometimes it may feel like it's going straight up for a second, even with a 90hp.

[JimInPB]

I have an old OMC 100 on the back of my 17.  It's the same block as a 115 & weighs in at right around 300 pounds.  The boat sits pretty level in the water with me at the helm, but water comes in if I walk to the back.  That's just the way that a lot of little 17s are.  A lot of Key West 17s are considerably worse that way.  Ping pong balls are a big help with that situation.

I don't know which Yamaha you have, so I can't look up your motor's weight for comparison.

A 115 is a lot of motor for that boat, but not over the top.  If you already have the motor trimmed all the way down, you may need to work on getting the feel of feathering the throttle a little.  Small boats with big motors can be a bit touchy. 

[Parthery]

The Yamaha 90 is a 3 cylinder....the 115 is a V4, hence the weight difference.

On my '74 170 (repowered in the mid 80s with an Evinrude 90 V4) I added transom wedges for some negative trim....that got the bow down and worked well.

[Fletch170]

Strange...

My 17 had the same motor, running a 17 inch pitch blade....she jumped right up on plane. I would suggest punching it out of the hole

[CTsalt12]

Yikes seems like too much weight.  How much water are we talking about here?  I have a 175 with a 115 that seems like very little difference.  Maybe you're just not used to it? 

Sandbag in the box below deck should  help scuppers and also keeping bow down a bit.

[larsli68]

Hello,
for what it's worth. I have a 1981 Aquasport 170 with a Mercury Optimax 115hp.
I raised the scuppers with 3/4" and the boat is dry, except when I'm in the stern taking the anchor. I get some water in the boat, not bad, but I have gotten used to using
my gore tex shues, not my sneakers... The water here is not Florida warm... I'm in Sweden...
I probably would have raised my scuppers with 1" if I would do it again.

//Lars