Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Mounting 115 HP Evinrude on 16'-7" Whaler

Posted by Ice Cop on 01/28/10 - 4:33 PM
#1

Good evening all. I have recently acquired a late 60's 16'-7" Whaler. I know what the spec's say regarding engine size but I have a 1989 Evinrude 115 that I would like to mount.

Can this motor be mounted safely? Do I need to drill below the bottom of the splash well to do so? The old engine (not sure how big) was mounted with one set of bolts and crank downs as found on older smaller outboards.

My preference would be not to drill any lower that the bottom of the splash well if possible as I do not know how good the wood in the transom is. I have seen several pictures of 115-120 hp engines mounted. Do you raise the engine up before bolting it on?

Any help would be great.

Thanks

Edited by Tom W Clark on 01/29/10 - 9:00 AM

Posted by HarleyFXDL on 01/28/10 - 5:33 PM
#2

The max hp for your boat is 100hp. The 115 and 100 Johnson/Evinrude are the same size and weight. That being said, Can your boat handle a 115? Yes it can. Only you can make the decision whether to over-power your boat by 15hp.

As far as the bolt pattern, I'm not sure how your splashwell is configured. I would imagine you should be able to have all four bolts in the splashwell. There are others here that can confirm this.

Posted by Tharsheblows on 01/28/10 - 6:31 PM
#3

You can always mount it on a jack plate.
As for overpowering I would, but I would remove the engine if I sold it. I have been told that if the boat is in a accident that can be in anyway blamed on overpowering no matter how many times it has changed hands the liability falls on the one who powered it.

Posted by tom blinstrub on 01/29/10 - 3:31 AM
#4

The newer engines all have a standard bolt pattern. The bottom bolts on my 16 angle upwards and just make it into the bottom of the splashwell. If I were to change engine brands the same holes would be used as long as it was a newer engine. I am not sure what year the different engine companies standardized the bolt patterns. Maybee someone at this site can give us an exact date. 100 hp is more than enough hp. LOL

Posted by jollyrog305 on 01/29/10 - 5:08 AM
#5

Our 67 Currituck (16’7”) has an 85 Johnson 115 on it. All four bolts fit fine in the splash well. There is even enough room for some rather large square washers.

Posted by theo on 01/29/10 - 8:39 AM
#6

15% overpower is pretty trivial for a Whaler.

Have you seen this article?
http://www.whalercentral.com/articles...icle_id=82

You can compare the dimensions with your engine, but I'll bet any late 80's Evinrude is BIA.

You can make a paper template of the BIA pattern and hold it up to your transom. You could also just suspend the engine over the transom and see where the holes fall. Common knowledge here and "elsewhere" says you want the cavitation plate about an inch above the keel.

I agree, a jack plate would be useful if you want to try to optimize the engine height, or if you just can't get the BIA pattern to work for you.

Edited by Joe Kriz on 01/29/10 - 11:27 AM

Posted by Tom W Clark on 01/29/10 - 8:56 AM
#7

Mount the motor "two holes up" using the third set of top motor mount holes and the top set of lower motor mount holes.

Do NOT use the blind bolt holes.

115 HP is fine on a 16'7" Whaler. It is a very common and desirable power option.

Yes, the 1989 Evinrude 115 uses the same BIA standard bolt hole layout as all other large outboard motors made since 1984 and all large OMC/BRP outboards made since 1960.

Posted by finfish04 on 01/29/10 - 9:02 AM
#8

Tom, I am curious as to why you do not recommend using the blind bolt holes on the motor mount. Thanks , Dino

Posted by Tom W Clark on 01/29/10 - 9:05 AM
#9

The motor will be too low and you will not be able to adjust the height in the future.

Posted by Binkie on 01/29/10 - 2:26 PM
#10

I would definitely not mount a 115 on a 16 ft. Whaler. I would look for a nice clean 140 and mount that. It is still a V4 and about the same weight. Remember if you ain`t skeered, you ain`t having fun!

Posted by HarleyFXDL on 01/29/10 - 3:47 PM
#11

Binkie, could I be your beneficiary? ;-)

Posted by modenacart on 01/29/10 - 5:17 PM
#12

I would let the insurance company know so you don't void your policy.

Posted by barrydm on 02/09/10 - 6:11 PM
#13

To use a 115 on a 16' 7" whaler, I assume you would need to find one with a 20" shaft?

Regards,
Dave

Posted by Tom W Clark on 02/09/10 - 7:26 PM
#14

That is correct. All 16'-7" Whalers use 20" (Long) shaft length outboards. The good news is that is the most common shaft length ever made so its easy to find such a motor.

Posted by whalerman on 02/10/10 - 7:52 AM
#15

Hi, as a former '82 sport 17' BW with a 115 hp Johnson owner, the only thing is that you have to be carefull is where you run wot. With the engine trimmed out she would start to chine walk with just me in it at wot. As memory serves the prop was a sst with about a 21" pitch. I would trim "in" to where she would stop "walking" and enjoy the ride. Engine was mounted "down", meaning the av plate was even with the keel. I did use the "blind" lower holes that were in the bracket. Bolts were in the splash well area. I think the older 16's the splash well size is differant, Joe or Tom would know more about that aspect. The 115 hp - go for it, 140 hp, NO

Posted by Ice Cop on 02/15/10 - 9:50 AM
#16

GENTLEMEN, THANKS FOR ALL YOUR THOUGHTFUL REPLIES, AS THE WEATHER WARMS UP HERE IN BOSTON I'LL BE GOING FOR IT AND MOUNTING THE ENGINE. I APPRECIATE THE ADVICE ON THE BLIND HOLES BUT WOULD LIKE ANY MORE INFO REGARDING THE DIFFERENT SIZE SPLASH WELLS ON THESE BOATS.