motor mounted on transom.... wobbles

phatmanmike

Captain
Joined
Oct 24, 2003
Messages
3,869
1960 glasspar citation 16 foot runabout with 1976 merc 1150 inline 6cyl<br /><br />origonally came with 50hp evinrude i believe, maybe a 75....but NOT a 115 merc, they werent invented yet...<br /><br />heres the question..<br />the motor mount holes seem really close together, closer than my big evinrudes are, and i think its making the transom wobble. can i put a plate of aluminum uner the bolt holes to spread out the pressure?<br /><br />m ikey<br /><br />ps if anybody know what motor these things came with in 1960, i would really apreaciate it(sp)
 

Ken G

Petty Officer 2nd Class
Joined
Feb 28, 2003
Messages
158
Re: motor mounted on transom.... wobbles

An aluminum plate may be a band aid fix that may leave everything at the bottom of the lake some day. It sounds like you may be ready for a transom core replacement.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,571
Re: motor mounted on transom.... wobbles

Mike, You may simply have too much power on that boat. It is likely the highest HP motor made in 1960 was 100HP, and it was used on larger boats(18-22'). I had a 1967 16' Winner runabout (about 300 pounds in weight). It came with a 50HP Merc, and I eventually got an 85HP motor. I was afraid to run at WOT, since the speed at WOT was 45+MPH, and the boat was substantially less than 1/4" thick glass in some areas.<br /><br />Currently, I have a 3/8" aluminum plate covering the entire transom of my 16' speedboat (1977 Merc 1500). I am convinced this plate has great benefits in protecting the transom form the power of the motor. My speedboat is low profile and wide and at 700 pounds in weight, it is built very strong. <br /><br />I would think you need to evaluate the strength of the glass on your boat, the type of hull and other factors to determine if it is safe to run 115HP. If it is, the aluminum plate is a good answer.
 

phatmanmike

Captain
Joined
Oct 24, 2003
Messages
3,869
Re: motor mounted on transom.... wobbles

well in 1960, the biggest available was the evinrude 75v-4, but it wasnt available from the glasspar factory. you had to get it aftermarket. the biggest stock motor these boats actually came with was the 40hp evinrude. about 200 pounds lighter. this motor was there when i got the boat.<br /><br />i being of sound mind understand that this is way too much hp for this boat. motor is too tall and too heavy and too much hp.its real fun though<br /><br />as for now, its all i have that i can put on it.<br /><br />i LOVE the motor, its soo clean and new looking, and it runs absolutely like a dream, i dont have a nother hull safe enough to put it on.<br /><br />i just wanted to know what types of temp solutions i could use in the meantime till i get another hull...i payed 800 for the whole thing, boat , motor trailer... ive already junked the trailer...<br /><br />thanks for all input guys. much apreciated<br /><br />m ikey
 

quantumleap

Master Chief Petty Officer
Joined
Feb 16, 2004
Messages
813
Re: motor mounted on transom.... wobbles

Reinforcing it with a plate may just overstress the transom edges, especially where it joins the floor/stringer area. I would go easy on it and shop for a bigger hull if the motor is as nice as you describe. You would probably have better luck finding a solid boat with a dead motor than a clean bare hull. Keep in mind your nearly 3 times over powered right now. Be safe.
 

phatmanmike

Captain
Joined
Oct 24, 2003
Messages
3,869
Re: motor mounted on transom.... wobbles

thanks, ive been looking for a old(cheep)17-18foot bowrider or centerconsole, but havent found anything yet....if you see sometin', shoot it my way
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: motor mounted on transom.... wobbles

Have you actually seen it wobble or move in an inappropriate way or is it an assumption based on the narrower bolt spacing? I had put an 85 horse Merc inline six on an early 60s 17 foot runabout, and it went faster than the hull design allowed for. Straight lines were not bad, but turns could brown your trou in a heart beat. The first time it spun out on me I was sitting a few inches higher, and learned not to do that again. Never noticed any flex or strength issues with the hull, just the speed handling issues. Aluminum plate may help a bit, but a hull that can handle the juice or rebuiling your transom from scratch to have more strength is your best bet. Good luck...
 
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