Overpowered and Crazy? or What could it Hurt? XR6 on 17 foot boat?

[EMC 2870]

First off I would like to say I have been around a while, but mostly as a lurker. Please let me know if this is not the proper place to post this. I have a 17 foot Allison Marine Center Console with a little 75 Mercury 3 cylinder on it. I have been itching to replace the motor with something bigger for quite a while. Well last weekend the gearcase gave up the ghost is spectacular fashion. The boat is rated for 115 HP but I am just not a fan of the 115 2+2 motors of the era. Would I be crazy to hang a XR6 150 off the back? I don't think weight would be an issue. My 75 weighs in at 305. The XR6 is about 390. I have two batteries I can move up to the console to more than make up the difference. Am I crazy? Should I just give the L4 a chance? Or am I on to something with the XR6? The other option is to get a new gearcase and just put around for a few more years. What would YOU do if it was yours?

[Ted Stryker]

I'm reasonably familiar with most Allisons but I'm drawing a blank with the description you gave.. Fishing boat, or competition hull..? pics..?

[EMC 2870]

I will have to hunt down pics. It is a shallow V Delta pad bottom, standard chines, with a center console top rather than a dual. From what I understand is that this is a pretty rare boat because they didn't sell well at all. Depending on who you ask it was only made in 96 but sold as new for 96 97 and 98. Again this is all hearsay because no one seems to know much about this boat.

[pyro]

Most people hang that kind of power on these to begin with.

The big problem with the L4's is that they're not designed to turn big RPM.

[transomstand]

Horsepower ratings are pretty much meaningless in regard to what a particular hull can tolerate. The ratings are based on a formula calculated from hull displacement issued by the Coast Guard, and are extremely "generic".

The real question is, can the boat be operated with reasonable safety at the intended speed (feeling like you're going to die every time you set foot in the thing is not enjoyable for many).

Considering that around here, 200 horsepower on a 15 foot hull is fairly common, and 300 horsepower is not unheard of, if you don't hang the XR6 on that thing, you probably won't fit in well:D

Post a pic first, we want to be sure you're not trying to hang it on a rowboat:D

[EMC 2870]

I took some pics but I don't know how to post them, here.......

[transomstand]

http://www.screamandfly.com/showthread.php?144623-***-Posting-Photos-The-Easy-Way-Please-Read-***

[RNM018]

Allison Craft , or Allison Marine ?

I'm not familar , with Allison Marine , and don't beleive Allison Craft , has built anything smaller , then a 20' boat sense the early 80's or before maybe .

I sure would be interested , in seeing pictuces , before offering advise .


Rich Martin 018

[SANTAFE]

When it comes to power, and other things, it's better to have and not need, than to need and not have!

[EMC 2870]

Allison Craft , or Allison Marine ?

I'm not familar , with Allison Marine , and don't beleive Allison Craft , has built anything smaller , then a 20' boat sense the early 80's or before maybe .

I sure would be interested , in seeing pictuces , before offering advise .


Rich Martin 018

Definitely Allison Marine.

Here are a few pics from my phone.

http://i71.photobucket.com/albums/i138/Christophers_2006/20130727_123154_zpsdcb7b436.jpg (http://s71.photobucket.com/user/Christophers_2006/media/20130727_123154_zpsdcb7b436.jpg.html)

http://i71.photobucket.com/albums/i138/Christophers_2006/20130727_123224_zpsd2e292da.jpg (http://s71.photobucket.com/user/Christophers_2006/media/20130727_123224_zpsd2e292da.jpg.html)

[EMC 2870]

Here is a photo of the pinion and forward gear........

http://i71.photobucket.com/albums/i138/Christophers_2006/20130724_162748_zps9443fadd.jpg (http://s71.photobucket.com/user/Christophers_2006/media/20130724_162748_zps9443fadd.jpg.html)

[RNM018]

Gotcha !

Pictures are worth a Thousand Words !

Just check the hull out real good , and be sure it got no structural issues , and use some good steering .
That should be fine , with a 150 on it .

Good Luck , with your project !


Rich Martin 018