NEED HELP choosing the right HP!!!

[snowmobilefanatic]

i have just recently got a 14 foot light weight fiberglass closed bow boat from the early 70's late 60's. the fiberglass is still good and flexes and i just did alot of transom work to it. the boat is MUCH lighter than a alum boat, i can pick up the boat twice as easy than a alum, i have a 14 alum from the ealry 90's so i can compare. the fiberglass is around 3/4 of an inch thick, ive thought that might be a little thin. i used a 75 evinrude 15 horse on the alum boat.... do you think it will be able to handle it??

 

[Texasmark]

Re: NEED HELP choosing the right HP!!!

Have no idea. Haven't seen the boat.<br /><br />One thing about chopped fiberglas is that it will come apart if it flexes. Usually boats are made with hand lay woven mats in the hull and the chop (if used) is used as a backfill stiffner and doesn't flex. I know of none that use the chop as the only element of the hull mfgr (excluding non-load bearing gell coat).<br /><br />And too, fiberglas is just that....glass. The rosin makes it stiff, but if you bend it it will eventually break.<br /><br />But the weight difference between a 15 and 5.5 is not much and nothing says you have to run it wide open.<br /><br />Mark

 

[snowmobilefanatic]

Re: NEED HELP choosing the right HP!!!

about the flexing part. its stiff, but it will flex when needed to. say like hitting a good size wake. ive always thought the fiberglass is supose to flex when hitting something so it doesnt break, my old mans 74 glastron 18' I/O hit a wake while going up on plain and the whole boat flexed in the midddle.... i can get pictures of it to show on monday. i dont have a digital camera. i dont want an engine too big to break the hull or somehting like that. with a 15 horse it whould go 30-35. i think that might be a little to fast for the amount of fiberglass that the boat has. this is what im asking. do you think a 15 whould be to fast for the boat

 

[roscoe]

Re: NEED HELP choosing the right HP!!!

go for it, slow down if it goes too fast.<br />most glass boats are thinner than 3/4 inch.

 

[tashasdaddy]

Re: NEED HELP choosing the right HP!!!

are you using tiller control or remote. this make a big difference. you alum boat must be a heavy, as i have found most alum are lighter than fiberglass for there size. i have a 14 Lone star open fishermen semi V with a '55 15hp rude. to fish by myself, had to go the remote control at the middle seat. ezy glide stick steering, older rude shift/throttle. now it is my favorite boat for fish and play. will pull up a 175lb skier with 2 ski's.

 

[cobra 3.0]

Re: NEED HELP choosing the right HP!!!

I have a fiberglass boat as you describe and put my 15 Evinrude on it. Works just fine...HOWEVER, BE CAREFUL because my transom was completely rotted out when I first tried it and bent back and almost snapped from the thrust of the 15!!!! <br /><br />My plywood was wrapped by an outer and inner fiberglass sheet, so you couldn't see the wood.<br />It must be your transom that is 3/4" thick, not your hull. Your hull is probably only about 1/4" thick.<br /><br />I put in fresh plywood and reinforced the fiberglass at the back. Now it is just fine. The original 6 hp Suzuki I had on it did not flex the transom so I had no indication of it initially being rotten.

 

[Texasmark]

Re: NEED HELP choosing the right HP!!!

Yeah, I've seen the sides of some glass boats flex too and in not too many years you start seeing cracks where the deck meets the sides...MFG to name one.<br /><br />Then there was the time I was in Crystal River Florida and I got a guy to guide for me. He came to the dock in this 20 foot "thing" with a rude 85 on it. Never got it over 1/4 throttle and I was glad because as we went onto waves and over things the whole floor pulsated.....stringers must have rotted out.<br /><br />Couldn't wait to get back to the dock and no we didn't catch any fish.<br /><br />Did see a couple of Manitees.<br /><br />Mark

 

[snowmobilefanatic]

Re: NEED HELP choosing the right HP!!!

cobra 3.0, your exatly right the hull is a 1/4 but the transom is 3/4. my transom was also warped and rotted pretty bad but i replaced it with marine plywood and it can hold me (145pounds) on top of it wiggling it and it doesnt budge. but there is only fiberglass on the back of the transom not the front of it. this is how it was before so i did it the same way it was before. its set up for remote. it has a steering wheel and spot for controls. looks identical to the old wooden boats form the 40's and it has wings in the back like old t-birds. the top is all one peice, the seats and the bow top and rear seat are all one. looks pretty cool. i dont kow the manufacture of it. it doesnt have anyhting on it to identify it except for a couple of swans painted on the side lol, i repainted over that.

 

[tashasdaddy]

Re: NEED HELP choosing the right HP!!!

i would want more than a 3/4 " transom. i would atleast add another 3/4 X 8" piece across the top and glass it in.. sound kind of like it had been replaced before. i know the old boats with the fins. late 50's early 60's. beef up the transom, find a rude 33 and make it original.

 

[snowmobilefanatic]

Re: NEED HELP choosing the right HP!!!

i use to have a old evinrude 35. the thing was so heavy i couldnt pick it up. i think 33 horse power whould be over whelming for the hull.<br /><br />cobra 3.0, how fast whould you say your boat goes, and how good is the gas milage.

 

[tashasdaddy]

Re: NEED HELP choosing the right HP!!!

if you could post a picture it would be a big help.

 

[cobra 3.0]

Re: NEED HELP choosing the right HP!!!

Speed with you alone can be around 25-28 mph. With 2 people around 21-23 mph. My 15 is a "recent" 1998(used only a few times a year) and it has lots of punch. Yours may vary a few mph as I don't know what year it is and its condition. Mind you your boat has wings and it'll probably start flying after 20 mph!!!LOL <br /><br />Gas mileage isn't a concern. A tank will last you all day long and then some.<br /><br />I agree with tashasdaddy, double up the plywood the top 8 inches or so.

 

[snowmobilefanatic]

Re: NEED HELP choosing the right HP!!!

im guna try to post a picture of it asap. i dont have a camera so im guna have to barrow one, i need to anywase to sell my ski doo olymique snowmobile and other misc things. thanks guys for all the help this site is great!