Max hp help

spooner_jr · September 18, 2012

I have an older 18' heavy, aluminum deckboat, bought at least second hand, and the plate with the hull rating has gone missing. I'm looking to re-power the boat and would like to find out the max hp I can use. The boat was originally bought from Buckeye Marine, but when I contacted them, they had no clue. Model is not listed under iBoats. It's a late 80's, Peteborough Admiral 185. Current motor is a 60hp. Any help or ideas would be appreciated.

vance · September 18, 2012

Not much on the net anywhere about your boat but I did find this site that has brochures. http://www.boatingwithdawsons.com/old-boat-brochures.html

They charge $25 for a pdf brochure and it is hard to tell if your boat is actually listed under the name you have.

vance

craigdritchie · September 18, 2012

Peterborough sold at least four different models of aluminum deck boats as part of its Admiral series. Your 185 is the smallest model of the four. There was also a 22-footer (Admiral 225), a 26-footer (Admiral 265, which had a standard hard overhead canopy that doubled as a sun pad) and a 30-footer (Admiral 300, a double-decker for almost its full length). Both the 26 and 30 could have a camper top option, so you could completely close them up and camp out for a few days in nice weather.

The Admirals were sold from 1984 until the Peterborough company was acquired by Alcan Group in 1990. Alcan had other ideas for the company, so 1989 is the last model year for these. All Admirals were fairly rectangular in shape, very stable, and just about bulletproof. There is a similar boat series built by Peterborough called the Sunliner, which was also sold in 18-, 22- and 26-foot versions. The Sunliner was basically the same thing as an Admiral, but was stripped down with fewer features and cheaper seats / carpet, so it could be sold at a lower price.

Both the Admiral and Sunliner boats have relatively low freeboard, so the 60 hp on your boat is probably close to max power. I can't find an actual max power rating for the 185, but according to my reference (an old catalogue) the 30-footer tops out at 175 hp, and the 26-footer is rated to a 150. If we work that backwards, the 22 would probably be somewhere around 115 hp, so your 185 likely tops off at around 75hp. It might be okay with a 90, but as each of these boats gets progressively narrower, as well as shorter, maybe not.

The biggest worry about putting on an engine that's over the boat's rated capacity is that if you ever have an accident, you're almost guaranteed to be sued. And, your insurance will not cover you if you're over capacity.

I'd suggest you contact Transport Canada's Office of Boating Safety at http://www.tc.gc.ca/eng/marinesafety/debs-obs-contactus-menu-2982.htm. They will have capacity plate records for every make and model of boat ever sold in this country. Or, try contacting Princecraft (http://www.princecraft.com/aluminum-boat/About-Princecraft/Contact-us.aspx). Princecraft bought Alcan many years ago, and would subsequently have old Peterborough records in their files.

My gut feel is you're probably fine to 70 - 75 hp. But, better to check before you plunk down a lot of cash on a new outboard.

Edited September 18, 2012 by Craig_Ritchie

spooner_jr · September 18, 2012

Wow, thanks for the information.

I'm hoping it's a little more, as with the 60 on the back, it's hard to get the nose up out of the water unless you have 2-3 people sitting at the back. It gets up on plane, but even trimmed way up it tends to plow the waves.

Woodsman · September 18, 2012

I'm hoping it's a little more, as with the 60 on the back, it's hard to get the nose up out of the water unless you have 2-3 people sitting at the back. It gets up on plane, but even trimmed way up it tends to plow the waves.

That may also be a improperly sized prop instead of lack of hp.

With a deck boat you may have too high of a pitched prop not allowing the motor to reach full rpm's.

Do you have a tach to confirm you are getting at least close the maximum rated rpm of your motor?

ScubaJoe · February 28, 2023

Thanks for the information @craigdritchie!

With a "little" gap from the last post, I was hoping someone from the community can help me out.

I'm in somewhat of the same boat (no pun intended) as @spooner_jr, where the hull rating on my 1989 Peterborough Sunliner 225 can't be found. I have been searching for the dry weight (without a motor) of my boat with no luck.

I've reached out to both Princecraft and Transport Canada with the serial and registration numbers, but unfortunately they were unable to find any information.

From searching, I keep coming across this post and a history page of Princeville. (http://www.societehistoireprinceville.com/Photo_commerces_industries (Espadon).HTM) I've reached out to the Societe Histoire Princeville to see where they sourced there information and am currently waiting on a response.

Aside from finding a weigh terminal, does anyone have any ideas on where I can find out the dry weight for this old boat? At the end of the day, I'm really looking for a rough estimation to ensure I'm not exceeding the 5,000lbs tow rating of my vehicle!