Re-power 12' aluminium

Bubbles Up

Petty Officer 2nd Class
Joined
Aug 4, 2009
Messages
106
Hi boaters!

I have a 12 foot springbok(1967) aluminum that I am looking to re-power I currently run a 1979 7.5 Merc 2stroke, which is well with in the 10 HP rating for the hull. I like to troll flies or hardware,I have been thinking of a new(er) 4 stroke. No brand refused!
My hull weight is 85lbs transom width is 44 inches so I will need a short shaft.

I am looking for opinions that will troll s-l-o-o-o-w and still get me in quickly with a couple of 200lb guys in just in case need to get back for "lunch".I don't want to drag a sock or troll plate,looking for simplicity!

What would you do???
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: Re-power 12' aluminium

Realistically the only thing that will slow you down more than the idle speed in gear is more resistance. Simple as that.
Just my 2 cents though
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,778
Re: Re-power 12' aluminium

Looking at a '94 Mariner catalog, 6,8,9.9. Only difference in powerhead and gear ratio is WOT rpm. All have same cubes and apparently the hp is limited by choking the smaller ones down which limits the WOT rpm to lower values for the smaller engine. All probably idle at the same 600-1000 rpm whatever number the designers chose in that range and all probably idle at the same value. All come with the same prop as standard and have available the same prop pitch ranges. All weigh 69 lbs.

So the choice to me is clear as a bell. l Get the 9.9 to stay within your 10 hp limit.

Have fun.

Mark
 
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