14' Starcraft Seafarer 72

[nnl1987]

Hello I was hoping someone would be able to help me out with a boat I recently inherited from my father. I have been slowly in the process of restoring the boat and have issue with the boat performing bad at high speeds, you are going to have to bare with me I don't know all the technical terms so here goes my explanation of what happens.

The boat will nose up properly when you throttle up and come back down. After it comes back down and you begin to increase the throttle further the bow of the boat begins to sink to fair into the water the is hard to control and you get a lot of spray coming up the front sides of the boat. I have tried adjusting the tilt pin on the motor to see if this helps but it doesn't seem to matter what pin you put it in you get the same performance. In fact you get some cavatation in one of the pin positions.

This boat use to run fine with this motor on it without problems at higher speeds, then one day it just started. The transom was in bad shape when I got it but since then I have replaced it with 3x 3/4" plywood as you can see in the picture, thinking that this was the problem but no change (due note that it was run for years and years with a bad transom). I have uploaded several other pictures of the boat as well. Is it possible that the years it was ran with a weak transom has damaged it further then just replacing the plywood that was there.

Any thoughts would be appreciated.

 

[southkogs]

From the photo on the trailer, it looks as though the boat is sitting on some wood that runs across the keel. Is it possible that the hull is hooked? That's not an actual boat trailer with bunks, so I'm wondering if there's a bend in the hull due to that.

A 25HP on that boat shouldn't plow, especially if you're trimmed all the way in.

 

[DeepCMark58A]

That transom scares me, the deterioration of the aluminum would concern me as well.

 

[nnl1987]

There is no pitting of aluminum as of yet. The only thing missing in the picture of the transom is actually the top piece of aluminum that covers the top part of the plywood. There is no flexing of the transom anymore, believe me there was a lot there before it was replaced. I plan on using marine grade plywood and ordering aluminum to go across the back to stiffen it up even more. Looking at factory pictures of the seafarer that I have managed to find online its pretty close to being back to factory. They where sold believe it or not with 2x 3/4 pieces of plywood for a transom with a aluminum top trim piece to just spruce up the look of it.

As for the boat trailer not actually a boat trailer you are correct in your thinking of that. I often wondered if the trailer has indeed bent the hull of the boat from being strapped down on top of it. I don't exactly know what you mean when you say if the hull is hooked. I could take a picture of the boat trailer if you wanted.

 

[nnl1987]

There's actually a 16' Starcraft Seafarer from the same year, around town where I live. I haven't looked at it to closely yet to compare to the 14' that I have. I assumed that there would be a difference in measurement and angles it being a 16'.

 

[southkogs]

I don't exactly know what you mean when you say if the hull is hooked. I could take a picture of the boat trailer if you wanted.

What you want to see is if the hull has a "bend" in the bottom. Run a straight edge down the keel and see if there's any kinks or bends in the metal. If the bow is bent down a little from sitting on that wood, that could cause you to plow.

 

[nnl1987]

Well I finally got around to flipping the boat upside down. There's no bend in the keel, there's a few spots where the straight edge doesn't touch but only a 1/8th to 1/16 and only for a inch or so at a time. The rest of the hull is not in perfect condition that's for sure, few area's where there's dents and such I will work on bringing them back to what I think is close to being factory. Not sure if that would affect performance at all.

I also managed to stop by the 16' Starcraft Seafarer from the same year and put a angle gauge on it and compare it to my own. The angles at the transom are pretty much the same, difference of half a degree maybe. I also did some research and put the carpenter's square on it found it's 12 degrees which is the most common transom. Running out of idea's except for maybe reinforcing the transom further or trying a different outboard motor all together.

 

[southkogs]

Any idea what the weight of the boat is as originally built, vs the weight now with the added wood inside? Maybe that's a factor?

 

[Watermann]

Welcome aboard :wave:

With the issue you describe is the opposite of 90% of the boaters, usually the stern is heavy in the water rather than the bow. What do you have up in the bow for weight?

Your Seafarer is rated for a 20 HP motor rated at the flywheel from the same era rather than a newer 25 HP that is rated at the prop.

What in the heck is that in the pic below? Fresh sillycone? and is that smeared wad of carp on the bow?

 

[flyingscott]

That bottom looks horrible. I have the same boat a 1974 model rated for a 30 hp and weighs about 200#s thereabout. I run a 1987 25 hp merc and my boat is VERY bow light takes 3 anchors and a battery to settle it down. I would look at all the garbage on the bottom of that boat and see whats going on there.

 

[nnl1987]

That is yes silicon, one attempt 10 years ago to make it water proof until I figured something out last year. I never bothered to clean the hull, didn't know if that would affect it at all. There is also some silicon build up at the back of the hull were the bottom of the transom meets the hull.

Weight should be relatively the same versus when the boat was originally built. The only additional weight difference in the boat is the boat boxes that where built into in, think I uploaded a picture of them in the first post I made. They are located more towards the back of the boat however so I think they would add to bow lift not hinder they probably only add 25 pounds to the boat. If the weather ever clears up, I will clean up the silicon.

Is there some sort of golden rule or formula when the keel and hull of the front of the boat should start to curve and taper upwards to the bow? Or is each boat different?

 

[southkogs]

Is there some sort of golden rule or formula when the keel and hull of the front of the boat should start to curve and taper upwards to the bow? Or is each boat different?

Different for each hull design. Different hulls are designed to work with/through the water at different speeds and attitudes.

Watermann kinda' said what I've been thinking ... really weird that you're plowing. Most of the time people can't keep the bow down. I suppose the silicone could be doing it - I'm kinda' lost at the moment.

 

[JimS123]

You said it didn't used to be this way. Thus, you made some change to affect performance. When you rebuilt the transom, did you change the height?

 

[nnl1987]

Unfortunately I don't exactly know the history of the changes that where made or if they just came about on there own, I inherited the boat last year my father he owned it before me (he was a poor caretaker of things and let the transom go, it ran with a weak transom I think for years). Yes as a kid this boat use to perform without any problems, no plowing through the water exact same outboard motor that has always been on it.

The height is as close as it can be to factory, I actually moved the transom up in height. My father had tried to cut it down to fix the problem without any luck. I did upload a picture with a straight coming out from the keel of the boat etc to show the height of the motor versus the hull, from my research I think the dept of the motor in the water is correct though I could be wrong. Keep in mind I am a complete amateur when it comes to these things. With any luck tomorrow I will be able to do some work on the hull, ran has been holding me back for a couple days.

It's no major problems if it never gets fixed, just means I can't go full throttle, only about 1/2 before it starts to dip.

 

[JimS123]

I have the same boat and the same motor. However, mine is a later model (with deep V hull - yours is a semi-V and mine is heavier with a factory installed floor). Your pic shows the engine to be trimmed level with the hull. Mine runs best trimmed up a notch or two.

My first trial would be to move the trim pin up.

 

[nnl1987]

Unfortunately again the tilt pin doesn't make any difference to the performance

 

[nnl1987]

Well finally managed to figure out what the problem was, the front the keel had a crack down the first foot or foot and a half, that was causing the boat to sucked down during operation. Any recommendation as to how to fix it, I have family that I think can weld aluminum. If they are not able any alternatives to what I have in there right now (just filled it with silicon to see if it would make any difference).

Now I have to remember to slow down a bit on my corners thing takes off like a rocket at full throttle.

 

[JimS123]

If it were planing properly the stem and front half of the keel would be out of the water and the crack would have no effect.

Your pics show the anti- ventilation plate is basically level with the bottom. I still say you need to trim it up. As I said before, I have the same combo - if my motor was level it would bow plow too.

 

[82rude]

Heres a far fetched long shot.Was that final piece of wood on the transom always there?If not maybe that addition changed the attitude of the boat?