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I will soon be picking up my new 1999 70hp Yamaha for my 1996 15' standard. The seller is keeping the stainless prop so I will run the aluminum one he is giving me for now. Any suggestions on rigging and prop selection would be appreciated. Speed is not what I'm after, good handling in rough water is.

Thanks in advance, Bill

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You want the 13-1/4" x 17" Stiletto Advantage 4.25 with a DE-500 hub kit.

Be sure to mount the motor as high as it can go on the transom, "three holes up"


o
o
o
o <-- Mounting bolts through this hole on motor's mounting bracket.

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Thanks Tom, this 70 looks like it belongs on here. I work a lot and between working on this and the "girlfriend", I haven't had much time to post pictures. I'll get to it one day. I'm not very computer literate.

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I finally ran the boat yesterday. I was told wrong on how to set the tach. Even though I tried every setting, I could not get it to read right so i don't know yet what wot was. I have the motor set three holes, all the way up with the Stiletto advantage 13 1/4 x 17 and was going about 40 mph according to my smart phone GPS. The boat pulled HARD!!! To starboard and would porpoise real bad when I got it into the wind. It was very windy yesterday and where I was is a protected channel with no current and no chop. It would run great though when i could get it out of the wind. I adjusted the engine tab and tach per instructions and going to try again today.

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As you stated speed is not your top priority I would drop the motor one hole. I tried to raise mine to the maximum height and the only thing I got out of it was blowing the prop out in tight turns. At the time this was my primary boat for pulling the kids on water toys. I am sure I could have spent money on a prop that might have gotten better bite but in the end that one hole up is not going to give you much benefit on that boat. I moved my motor up and down. I changed my prop from 17 to 19 pitch. With all set ups I ran 42 mph wot. I do not even have a tach on my old 70 so I can not speak to rpm change. I just know my boat handles better with the motor set a little lower.

I will add that you are going to love that boat with a 70. I tell everyone it is like driving a corvette on the water. Sitting down on the water like that 42mph feel like 62mph. The 15 will come off a wave as soft as any other boat you have ever ridden in. The smirked hull will provide a very dry ride. I love my 15, I want to go out and give it a hug right now.

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Bake, during my propeller endeavors today, I met a guy that offered me, well let me say more than I paid for the boat. We politely waved at the ramp and when we pulled away followed each other to the prop shop. Long story short he cant find the right prop for his flats boat and i can't get mine to quit proposing. He let me try his power tech stern lift prop and it ran flat and smooth, like it should. 34 mph at 6000 rpm. The only markings this thing has on it is scd3r13pym90. Looks like it might be a 13 pitch.

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Continued.... I got the prop at an excellent price. But I didn't sell the boat lol. I'll go by the next time I get some time off work and trade this stiletto 13 1/4 x 15p for a 13p and see if that doesn't do the same thing. All I know is with my friend in the boat with me today with that 17p prop it porpoised so bad it almost threw us out and I'm not exaggerating. He had to go to work so when i tested the power tech I was by myself. I hope it does the same , run right, when i have my gf or dad in it. The hull doesn't have a hook or anything like that so I don't know what the problem is that makes it porpoise so badly. I have looked at pictures of other 15s on here and mine is set up basically the same. The boat sits in the water with both splash well drains out of the water and level. I don't know.

P.s., I only weigh 185 so it ain't me lol.

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13 pitch 6000 rpm. I do not think that is going to be good for your motor. Off the top of my head 5500 to 5800 should be max.
I am sure I will be corrected but I did not take the time to Google it.
It is just my opinion but I think you will be happier if you drop the motor and get back up to the 17 pitch prop.
.

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Thanks Bake, I'll give that a try Monday.

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The 1999 Yamaha 70 HP two stroke has a 5000-6000 RM range and a 2.33:1 gear ratio.

I am confused about a number of things.



So the mounting bolts are going through the lowest set of hole in the motor, like this?


o
o
o
o <-- Bolts through this hole, motor mounted All The Way Up




Are you sure your phone is using GPS and not antenna triangulation to determine speed? There can be a big difference between the two and 40 seems too slow to me, so maybe there is a measuring error.



Again, I find that very odd. Usually when you have a motor mounted high, it makes the steering effort light. A motor mounted too low will often produce a lot of steering "pull".

Also, does it really pull? Or is it just hard to turn one direction? In 1996 Whaler would have been using a Teleflex NFB steering system so it should NOT be pulling at all. Please clarify.

How did the pull change as you trimmed the motor all the way out at WOT?

A PowerTech! SCD3R13PYM90 propeller is their version of the Yamaha Painted Stainless Steel model. It is a semi-cleaver design. This one would be 13" x 13" with a press-in rubber hub for Yamaha. 13" pitch is way too short for your boat.

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As for the porpoising, how is the motor trimmed? The only time my 15' porpoises is when I have it trimmed out for top speed and I slow down & leave it trimmed to far out.

The wind will affect the performance of the boat. A little bit of head wind actually seems to help my top speed when i have passengers. If have too much head wind it will raises my hull to much out of the water that induces uncontrollable chine walking at much earlier speeds.

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To the point that the prop can not cause porpoising. He is going much slower with the 13 pitch. That in itself will help the boat ride smoother because its down in the water.

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Good evening all, and thank y'all for all of your questions and comments, I really think I'm going to get to the bottom of this soon with all of y'alls help. Tom, I have the motor set all the way up, as high as it will go. Also I am using speed view GPS on my phone and if I would have let go of the wheel, me and the boat would have been into the rocks in .5 second. I mean it pulls HARD!!! The tab is not corroded in any way nor was it adjusted any, so I adjusted it a little and that helped some. As soon as I get a chance, I'm going to drop the motor 1 hole down and go back to the stiletto prop like bake suggests.

Again, I can't thank you all enough.

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You said that the boat pulls hard to stbd, did you move the trailing end of the tab to stbd when looking at it from behind the motor to compensate for the pull?

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Derwd24, I'm out of town and cant look at it bot I'm 99% sure I moved it, the trailing edge to starboard.

Thanks, Bill

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You say your boat is a standard model. Are you using a tiller outboard. If so, that may answer some of these confusing questions and answers.

rich

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Nice sweeeet13 binkie. My 15' standard has a side console just like a striper model but set up with thwart seats like a sport model. Look at the whaler models section under 15' standard and that one is my boat.

Thanks

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Here is Bill's (huckelberry145) 15' Standard.
http://www.whalercentral.com/userphot...oto_id=132

For some reason, for 1996 and 1997, the 15' models only came with the name of Standard 15'.
These Standard models had the option of the side console and thwart seats but Boston Whaler did not call that a Sport model like they did in the earlier days.
Just one of those stranger things they did back then?

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Joe is correct, the Standard name in the 1990s meant something a little different from the 1960s and 1970s.

The 15 Standard was available with, or without, remote steering. Obviously Bill's boat is remote because he is describes his steering wheel.

If the motor is pulling to starboard, we know two things:

The steering is non-NFB. This is odd, because the Standard's optional steering was explicitly Teleflex No Feedback (NFB) so while it might be very hard to turn the motor one direction, the wheel would not move if you let go. Somebody must have installed a non NFB system in your boat at some pint.

If the motor is pulling to Starboard, the motor is trimmed in. You didn't answer my question about how the pull changed as you trimmed the motor out. A (standard rotation) motor tucked in will pull to Starboard. When trimmed out, it will pull to Port. The trim tab should be adjusted for neutral steering at the speed and motor trim angle you must commonly cruise at.

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Tom, when I trimmed the motor up it porpoised so violently and pulled to starboard I think a little less. I know it still did but it's hard to judge how much when you think I think I'm about to get thrown out.

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Today, I dropped the motor 1 bolt hole and headed back to the river, with the stiletto 13 1/4 x 15. Just me in it, boat porpoised just as bad and pulled hard to starboard. Loaded the boat and headed to Charleston marine so Chris could look at this thing and tell me what I'm doing wrong. His synopsis: raise the motor and loose the stiletto. My next stop was Skips propeller where Mike let me hold a power tec 13x15. Went home raised the motor back up and put the new prop on and went back to the river. Still not enough pitch because I was hitting 6k before I was at wot, But, no porpoise, no starboard pull and I was running about 35 mph at 56/5700 rpm. I'm going to try an aluminum 13x19 that came with the motor to see what rpm that puts me at. Then I plan on getting a not so aggressive either power tech or Yamaha black stainless. I'll keep y'all up to date.

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I think i found the reason why my boat porpoises so badly. I checked my hull with a 6' straight edge again today and found a 3/16" difference between the port and starboard sides. It starts about 2 1/2 feet from the transom forward and is about 1 1/2' wide running from the centerline of the keel to the chine. It is basically a flat spot on the starboard side where the port side has a more rounded shape. Part of the fill and repair will be under the the trailer bunk. Will leveling compound work or should I cut it down to the glass and fill with glass and resin.

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I don't know, Huckleberry, that is a mighty small hook. I would think any influence it would have on the boat while on plane would be to cause it to lean to the opposite side. I believe that with the correct setup of the engine and the correct prop, the porpoising problem will go away. In certain conditions of waves and wind you can make any boat porpoise. I'm sure you'll resolved the issue.

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Huck,
That't the first thing we addressed with my 15, hull inconsistencies and design, then balance.

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I can't believe I didn't notice it but it makes perfect sense now. Now that I have found it, I see how I could have missed it. What I really want to do is find another 15' hull that i can look so i know which side is right before I start doing any repairs.

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Are you sure your not confusing the term chine walking and porpoising?

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I wish i were. This thing has been porpoising since I bought it, worse after I started trying to get the porpoise out of it, and extremely worse when i put the 70 Yamaha on it. This thing is dangerous to operate. It is so bad it is hard to describe. But, with the help of this site and the people on it i WILL get the problem resolved, properly.

Thanks to everyone for their help and input.

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If you need someone to do it for you or if you need practical advise, I can hook you up with my boat builder, Eric. He addressed these problems with hull mods.

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Thanks, I'll definitely keep that in mind.

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That sounds like a very small divot to be causing so much disruption in the boat sitting up on the pad. I will not say it can’t but it just seems that with a boat only running 35 to 40 mph it would not cause the bow to lift so drastically. Remind me if you ever run the 70 mounted further down and if it bounced when the motor was tucked all the way under.

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I don't think so bake, when the hull is on plane, or trying to be in my case and, my guess, 30-35% of the hull is deformed, I'm believing that this is my problem. I dropped the motor 1 bolt hole, all I can go without using the blind holes and there was no change in handling. I'm at the point of what else can it be. I'm going back to pick up the prop Tom originally suggested tomorrow, strip and flip the hull then fill and fair and see what that does.

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Again, I am confused. I thought you already tested that prop (13-1/4" x 17" Advantage) with the motor all the way up?

Have you gotten your tachometer sorted out yet? That is important data we have not yet seen.

38-40 MPH is still way too slow for that boat/motor/prop combination.

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Tom, I want to get the prop I originally purchased back and start from there for when i get the hull fixed. Tach is set properly now.

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OK, gottcha. Your boat should do 44-45 MPH at 6200 RPM.

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Thats what mine does with an F60. Good Luck.

If you're ever down towards Bluffton, I have an 1982 and an 1988 15's in the garage if you want to compare anything. Ever stopped by High and Dry Boatworks on James Island? Kirk has tons of knowledge on BW's. zot.

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I finially got the boat flipped today and found what I think is a bigger problem than I thought. Both port and starboard sides have a rocker but the starboard side is 1/4" bigger, a total of 1/2" from level. The keel is level and the chines are level but in between them it seems to flatten out. the thing is is it's not really centered over where the boat rests on the bunks. This is more than I can handle with my limited boat hull repair knowledge. I don't know what I'm going to do.

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were you planing on gel coating the bottom after you made the repairs?

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Bake, it looks like if I sand away the high ridge, I will not have much glass left. I'm almost at a loss.

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Can you post some pictures of what you're seeing?

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I wish I could but I don't own a computer, all I have is a smartphone and I can't figure out how to post photo links to wc.

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I don't know of anyway to upload a photo to any place on the Internet from a smartphone or tablet.

I know you can "Share" photos using email, Facebook, etc., but not actually upload them to places like photobucket, picasaweb, etc.

I have looked from some FTP apps but haven't found any.

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I appreciate your help Joe. Now that i have the hull upside down, I can see ridges all the way across the width of the hull fore to aft. I haven't seen many other members claiming of having a 15' standard. Kinda makes me wonder if most were taken back under warranty.

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Email me the photos and I will host them.

Here are the photos:

https://picasaweb.google.com/CascoBay...0734338114

https://picasaweb.google.com/CascoBay...3270822562

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Thanks Phil.

The pictures might be hard to read but there is a ridge port to starboard varying in thickness and width, except on the centerline of the keel. There are ridges all up and down the hull from fore to aft.

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From what I see you are going to have to build it up to flush it out. that will mean roughing up the bottom laying a layer or two of glass then some fairing gel coating. Its very doable.
On the 15 standard question. the hulls are all the same. The interior lay out is where the name standard came from.

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This boat was made very cheaply, I found a lot of things that support that statement after i bought it. I heard from an unreliable source that when boats are removed from the molds too soon these problems happen.

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That boat is 14 years or so old. I don't believe it's been like that since it came from the factory. After reading all your posts I'm wondering if the boat was on a trailer supported by bunks without any keel support and with a lot of weight inside, like full of water for a long time. It seems the only way that the conditions you describe could happen. It seems the foam has been compressed.

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That was my first thought too, but that doesn't explain the other ridges the rest of the way up. If that was the case, there would only be depressions where it rests against the bunks.

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Well, it may not have even been on a trailer, it could have been sitting on a pile of bricks but the most important thing for you to think about is how can it be fixed. It can be fixed, too. I wish I knew enough to tell you how. I'm sure everyone who reads this thread has an idea. I would aggressively sand the affected area with coarse sandpaper and fill and fare till it gives the profile you want. I don't know what to use as a filler, well again, I have my own ideas, but they may be wrong. I'm sorry you have this problem and hope it doesn't sour you to all Whalers. You are very discouraged now and when that happens its sometimes best to walk away for a while. We'll be here when you get back and maybe you'll be able to look at the problem from a different angle.

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Bake, this hull is only the same in shape, not quality. There are very obvious clamp marks of some sort along the gunnells along with other defects in the hull I mentioned. I can find only one 15' standard mentioned on another site and the owner has a thread complaining of the boat porpoising.

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With just me, 3 gallons of gas, a hydrafoil on the a/v plate and the motor two holes up the boat finally ran great. I still haven't ran with another person and a full tank so i hope everything stays the same when I do.

Thanks for all of the advice, Bill

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Huck,

The cupping that you see on your particular hull, may not be a manufacturing or design flaw alone. That type hull depression on the starboard side looks the hull was sitting on trailer or davit bunks that were too short for her. Make sure that is corrected or not the case when you fix this issue, the trailer bunks need to extend comfortably beyond the transom. I feel you on this. I knew before I even owned a 15 that hull mods were necessary. Extending the strakes to the transom fixes half of the problem and lessens the area that needs to be corrected immensely. I can say that in my particular project boat, the bottom work and modifications, accounted for the biggest portion of work, we joked about how the hull lacked symmetry. Luckily, we knew it going into the project.

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Actually, the trailer is fine. The bunks stick out three inches past the transom. I can tell by a watermark on the underside that The previous owner had this hull on one of those drive on boat docks. I think that it put just enough deviation in the hull to cause a problem.

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Just to clarify for others who may read this in the future, is the motor is now mounted in the second hole from the top? I think some would call that one hole up.

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I moved it back up to two holes up. That would put the a/v plate a little above level with the bottom of the boat.