Need help dialing in

matt88

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Took the maiden voyage this evening and have run into some problems. The data plate on this boat states that it has an 85hp capacity but it seems that there should be some weight in the bow or the motor is too big because the water line is about 2 inches from the top of the transom when I am standing in the back of the boat. At wot a lot of water is coming over the back of the transom and it is spraying water up like it is not trimmed out enough but it is trimmed as far as it will go. It is a 15ft fiberglass V with an 85hp mercury. Top speed as of now is 30mph on the gps. I was expecting 40-45. The prop is not in the greatest shape so thats on the to do list but I would like some advice on whether to put weight in the bow or not. Did this style of boat have a fuel tank in the bow? thanks in advance.
 

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matt88

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Re: Need help dialing in

Checked cavitation plate and it is about 1 or 2 inches below the bottom of the V. Shouldnt this be 4in above the V?
 

Bob_VT

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Re: Need help dialing in

Last time I answered a question you made a comment about my opinion.

Boats do not require weights in the bow. There are problems with your transom set up and motor set up. Cavitation plates needs to be even or 1 inch above the keel. 4" will kill your motor (fact not opinion) Mercury's have high water pick ups and if you go to high you will cook the impellar and motor if it sucks air and creates low pressure.

What prop is on the boat? With a ski-pole the PO may have it propped for skiing which requires hole-shot. What RPMS are you turning at WOT?
 

Woodonglass

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Re: Need help dialing in

Have you checked the Hull weight. She may be water logged. Not sure on that boat but if she has foam below deck and it is infiltrated with water she could weigh a LOT more than she is supposed to. Check the HIN plate again and see what she is supposed to weigh and then see if you can weigh her.

Again, I'm not sure but it might be a starting point. If the mfg rated her at that then she should be able to handle it, and the transom should not be riding that low.
 

matt88

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Re: Need help dialing in

You may be right about the water logged foam. I plan to pull the floor up this week to check it out. Bob, I wasnt sure about how high the cavitation plate should be above the V bottom,hence the ? at the end. I made a comment about your opinion because I was asking a question and your response was to inform me that I was trusting something that I knew nothing about. Trusting in definition is to rely on the truthfulness or accuracy of. Therefore if I was in fact trusting something I knew nothing about there would never be any need to ask the question in the first place. As far as having problems with the transom setup and motor setup. This is again is the point of my post. The subject title (Need help dialing in) should indicate that I am aware that there are problems with the setup. I do however appreciate you informing me that Mercurys have high water pickups. I was not aware of this and as a bonus it didnt seem to be based on opinion.
 

Bob_VT

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Re: Need help dialing in

Matt...... I saw a few things on your transom that raises red flags. The plate and the rods that pass through.

The ski pole stress......the supports for the pole should be forward of the pole and not behind the pole.

Check your prop and see what you are running....... investigate for water in the foam and in the transom.
 

Bob_VT

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Re: Need help dialing in

DSCN5798.jpg


This is a photo of my last merc/mariner set up. You can see the plate is above the transom and at that position I was getting 10 PSI of water pump pressure at the heads. I actually went up a whole inch more and had to block the upper water pick-up holes but blew up the water pump in the process and lowered it a half inch.
 

matt88

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Re: Need help dialing in

I will recheck it the way you done it with a level. You may have just saved me a lot of work because I was getting ready to pull it to the shed and yank the motor off. I believe I will pull the floor first now. I also plan to check the transom and stringers more thoroughly. It could just be water logged foam because my engine looks close to how yours is setup. I will report my findings later,thanks again.
 

matt88

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Re: Need help dialing in

Think I am done for this evening but I got the boat in the shed finally and tore up part of the floor to find wet heavy foam in the bottom. As far as I can tell the stringers might be ok. I found a few rotten spots but it seemed mostly solid. Will know for sure after I get the rest of the floor out and dig deeper. I stuck a level on the cavitation plate and it is 2.5 inches below the keel.
 

matt88

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Re: Need help dialing in

Guess curiosity got the best of me. Although a little of the wood in the stringers are wet in some places it doesnt seem to be all rotten. Think this might be ok after I clean it up and add another layer of fiberglass? The last pic is of all the wet foam I pulled out.
 

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Woodonglass

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Re: Need help dialing in

How much WEIGHT do you think that totalled up to????
 

Bob_VT

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Re: Need help dialing in

Yup...... someone rigged up a transom support from that pole and it does not look good.
 

matt88

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Re: Need help dialing in

Im guessing 250-300 pounds including the water logged sheet of plywood I pulled out in addition to the foam. It may be more. Some of the pieces on the bottom were really heavy for foam. As for the ski pole I want to keep it on the boat,but I agree that it will have to be redone. Planning on pulling the engine tomorrow to get a closer look at the transom. I want to see what is under the bandaid plates bob pointed out earlier. Thanks for the help guys. Even though this is going to be a bigger project than I had expected it will be worth it in the end.
 

Woodonglass

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Re: Need help dialing in

Yep, I bet your water over the transom problems will soon be over. Good luck with the rebuild
 

matt88

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Re: Need help dialing in

Got the engine off this evening and took a screwdriver to the back of the transom. Bob was right...Rotted to the core. Need advice on the easiest way to do this. Cut the whole top half of the boat off? cut around the back where the transom is at? or use seacast? Im not working with a huge budget here so cheap is the only way I can go. I can afford maybe two hundred dollars but not anymore than that at the moment. Unless my measurements were wrong somehow going the seacast route will cost me over 420.00. Does this sound right?
 

Woodonglass

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Re: Need help dialing in

You DON'T cut the top of the boat Off. You remove the rub rail(the rubber bumper piece that goes around the upper part of the boat) You will find either rivets or screws under the rubber piece. Drill those out and your will be able to LIFT the top CAP of the boat off in on piece. You will then be able to get to the transom. Sea Cast is expensive but not THAT expensive. You could do your for about $300.00. But I would use laminated Ext. Grade Ply coated with expoxy resin and 1708 Biax cloth. You could do the transom for $150 or less. It would last 50 years. If you want to check out a Seacast transom pour check out this guys thread. http://forums.iboats.com/showthread.php?t=364284&page=2
 

matt88

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Re: Need help dialing in

Thats what I meant to cut at the rub rail but I wasnt aware that a fiberglass boat had rivets or screws holding the cap on. That doesnt sound nearly as bad as what I thought.
 

Bob_VT

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Re: Need help dialing in

If you really want to "do it right" then removing the cap from the hull can be very rewarding. You will have 100% access ..........

If (and you do) intend to keep the ski pole ...... when you open up the hull you can build the support plates into the proper place. Skier's hitched to the pole tend to have stress pulling to the rear which requires front supports. The idea behind the ski pole is to move that stress and pull forward towards the center of the hull......... let's the boat pull a skier out faster and maintain control better.

Okay..... Seacast is fast and big $$$$ Nidabond is a bit less money and does the same job....... and 3/4" plywood sealed with fiberglass and resin is the least amount of the 3.
 

matt88

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Re: Need help dialing in

Got my stepson to help me pull the cap off this morning. It wasnt nearly as bad as I thought it would be. The transom however is complete mush. I am a bit confused though on how this transom is made. Is this another botched repair by a previous owner or does this look factory? It doesnt go all the way across the back. The piece that was bonded to the hull squares off a few inches from the edge and another piece that looks like it was loosely fiberglassed around the edges of the first piece even over the u bolt tie offs. The second piece was also a little more solid as well.
 

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Woodonglass

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Re: Need help dialing in

Interesting design. Back up a little with the camera so we can get a better OVERALL view of the thing from the inside looking towards the stern. Also a side cross shot would be helpful. It looks like there is a channel where a portion of the transom goes and attaches to the outer skin and then there are the set in out wings. Are those wood as well?
 
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