Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 1970 13' is a 40 hp honda to big

Posted by openwater on 11/28/11 - 9:36 PM
#1

I have a 1970 13' Boston Whaler and was looking at putting a 40 hp Honda motor on it. I going to install a transom adapter to make it a 20" transom. The motor weights approx 200 pounds and was wondering if this motor would be to big/heavy for this boat. I do not want to boat to sit to far down on the stern.

Posted by thegage on 11/28/11 - 9:40 PM
#2

Some people don't think that's too much weight, but others do. Do you already own the motor or are you going to buy new? If the latter, I think the E-TEC 30 is a great balance of weight vs. performance.

John K.

Posted by openwater on 11/29/11 - 6:28 AM
#3

I was going to buy a used 2001 40 HP Honda. I was looking at the 30 E-tec but this Honda is quit a bit less. Do you think my boat would still sit well in the water. Also how fast is your boat with the E-tec.

Posted by CES on 11/29/11 - 7:04 AM
#4

openwater wrote:
I was going to buy a used 2001 40 HP Honda. I was looking at the 30 E-tec but this Honda is quit a bit less. Do you think my boat would still sit well in the water. Also how fast is your boat with the E-tec.


If you raise the transom for the 20" shaft and move your battery and fuel tank forward.....perhaps under the aft bench seat, I think your boat will sit fine in the water with the Honda 40hp you mentioned above.

Posted by Phil T on 11/29/11 - 8:44 AM
#5

One way to know before spending money is to add the weight of the transom saver and the weight difference of new engine via sand bags, tool box or other elements to the rear while moving battery and fuel tank temporarily.

You can observe what the boat's trim will be and play around with the added weight o know what is too much.

Posted by contender250 on 11/29/11 - 12:32 PM
#6

Phil: Couple of things, I have seen 70-75 evinrudes on 13 whalers, the transom will crack at the corners. If you are worried about the 40 Honda I would do two things, 1st I do not care for the inserts for the 13 Whaler, yes I have seen a couple of them but still think it makes the boat look cheap. Second I would fill in the void with fiberglass and make it look factory, while you are doing this I would redo/enforce/reglass the corners of the Whaler making it stronger. This year I redid an 11 Whaler (1979) I raised the transom one inch and redid both of the corners with more glass. You have to look twice, still have the notch but not as short, it really came out nice.

Posted by kamie on 11/29/11 - 4:06 PM
#7

The general rule from Whaler is to keep the engine weight as far under 200# on the older hulls as possible. That should include the weight of the Outboard and any adapters. Have you looked at the Tohatsu 30HP, SS at 157# for manual tilt, no trans adapter required. You could go with the 40HP but that is 206#
with power tilt and no trans adapter required. I think the trans adapter is about 50#

Posted by cummings on 11/30/11 - 2:51 PM
#8

I thought the 40 honda would be too heavy when i was looking for my 92 13 GLS. I ended up with the 30 Tohatsu power tilt and all. About 185LB. I did not need to build up the transom. I think they make a 15" 30 also so you might avoid the modification. A little pricy about 4700 out the door if I remember correctly. Definitely less than 5K with a new tach, tank and all. Love it.

Posted by cummings on 11/30/11 - 3:54 PM
#9

Yup. They, Tohatsu, do make a 15" shaft for the 30hp

Posted by openwater on 12/04/11 - 8:57 AM
#10

Thanks for all your help. I buy the 40 hp Honda, now i just looking for a good transom jack plate to raise the transom 5 inches. I will post pictures when I am finished with my boat.

Edited by openwater on 12/04/11 - 8:58 AM

Posted by CES on 12/04/11 - 9:02 AM
#11

How about the Kentfab transadapter?? They are specifically made to fill in the gap on the 15" transom and raise it to 20" for the long shaft motors.

There's been many discussions on the forum concerning the Kentfab transadapter, just do a word search.

Posted by Jon197013 on 12/17/11 - 6:58 AM
#12

I have a 40hp Evinrude on my 1970 13' Sport. Custom made alluminum piece is mounted over cut out and either side of transom in order to support the 20" shaft and extra hp.
Aft seating is forward of factory position about 6".
Sits great in the water and is fast.

Posted by mojack on 12/17/11 - 6:16 PM
#13

openwater, I had a 13 sport and put a 40hp 4 stroke Yamaha on it. BIG MISTAKE! I know the Honda is about 20 or so pounds lighter but that won't make that much difference. This hull is extremely sensitive to too much weight on the transom. The boat will porpoise like crazy, even with one of those hydo-foil, whale-tail things on the motor. Even if you somehow moved the battery and gas tank forward, still too much weight. Did you already buy the Honda?
D

Posted by modenacart on 12/17/11 - 7:31 PM
#14

cracks in the corners on transomes is common.