BRS 17 motor size?

[Phil Stallings]

I am building a Brs 17 and hope to have it in the water in September. I haven't purchased an engine yet and was wondering if anyone had any ideas as to the HP I may need?

[sscoville]

I discussed this with Tom Lathrop some time back and I think he said he used an 8 hp on his BRS 15 at times and that it would plane.  He said anything greater than an 8 would be too much and speculated that a 9.9 would be about right for the 17.  Another BRS 17 builder in Tampa uses a 6hp Tohatsu.  He says it won't plane with this.  This model is the most hp for its weight.  I think it weighs about 60 lbs. 

[Tom Lathrop]

It depends entirely on what you expect the BRS 17 to do.  If its just a little get home power you want, anything from the little 2hp Honda up would do fine.  If you want to run as fast as the 17 will reasonably go, a 9.9hp would be about the limit.  I did try a 9.9 on my BRS 15 LOON and was able to get it to go faster than the 8 would do but it was not happy and I needed to stick on some temporary wedges under the stern to get the bow down.

This is primarily a result of Graham's design of the aft bottom on these boats.  The concession toward sailing ability in the BRS limits the planing ability.  The Bay River Runner is the planing and non sailing version of the same boat that has flat and parallel aft buttock lines.  The BRS is an optimum design for sailing, rowing and powering utility boat that will do just about any task and do it well.

[Phil Stallings]

Thanks for the info. This is my first build and I didn't know Graham had a Bay River Runner and that is probably the boat I should have built. At first I was going to add the centerboard and mast's but I decided against it because I will be moving from New Bern in 5 years to the foot hills of NC to retire on the family farm. The 10 acre lake on the farm wouldn't be much fun sailing. I am not to concerned about speed except to get off the water in case a storm comes up. I will mainly be using the boat to go back up in the creeks of Eastern NC to fish. I am interested in the temporary wedges that you mentioned. Will this help in getting the hull to plain and get more speed? Can you please give me some more info on what the look like and where to place them?

I glassed half of the hull on Friday and hope to do the other half tomorrow. Progress is slow because I have to work in order to be able to play with the wood. I am trying to get it done by September so I can use it before the weather gets to cold.

Thanks

Phil

[wkisting]

If speed is not an issue, I'd highly recommend the little Mercury/Tohatsu 2.5 and 3.5 hp motors, or the Honda 2 hp. The Honda is air-cooled and a bit louder, so I preferred the Merc. We use the Merc 3.5 hp to push our Core Sound 20 and it will maintain a speed of 5 mph at 1/2 to 3/4 throttle. Sometimes it will eke out 6 mph at full throttle, but it's not worth the extra noise and gas consumption.

Since the Merc 2.5 and 3.5 weigh the same (about 40 lbs.), I'd recommend the 3.5, which should push your BRS 17 very well even in a moderate current. If you anticipate strong currents where you might go, you may want to size up a bit more but we've never felt like ours was too short on power.

[Tom Lathrop]

The temporary wedges I used were made of wood and are similar to what may be found on many boats manufactured.  Their purpose is to lift the stern and promote planing in boats that were not designed quite right.  The builders and dealers may say otherwise but that is my opinion.  I don't really recommend that you mount such under your boat unless you are willing to do some experimenting.  I don't have the lines to these boats on hand and Graham is in Maine for a couple weeks.  Since your boat is already formed and glued up, I'd recommend waiting to see what he says.  

I don't want to be involved in butchering your boat or Graham's design by remote control.