Ok guys I need help to get an extra 3mph from my rig.
my engine is a 1995 evinrude 60hp, 56 cu in longshaft model.
its got the lost foam cast block and is the oval port engine. so no porting mods.
Now at the moment I can get 5900 rpm with a 13x19 omc sst prop and hit 42.4 mph on
my boat.
with 2.42 gears so getting just 4% slip. I think thats not too bad.
the hull of my boat is no race design, but slip shows its ok (I think)
I need to get to 45mph and here is the problem.
what I wanted to do was simply bolt on a set of the 70hp carbs to give me that extra
bit of oomph.
problem is that in the uk I cant seem to find any carbs that are from 1993 onwards.
I would of liked to stay with the same type of carbs as what was factory fitted, but it
looks like I might have to settle on something else. mine have the black plastic tops.
what other carbs will fit on my engine ?
could i simply use any of the 56 cu in motor carbs or could this create a problem ?
and what exactly is the difference between the 60hp and 70hp carbs?
from what I see its just the size of the venture being about 1/4 inch smaller on the 60's and different screw in jets.
is there any different passage ways or would these be the same in both carb body's
of same model year ?
as I have thought about getting my spare set of carbs machined out to the size of the
70 venturi's if its that simple .
I know everything else on the engine is identical apart from carbs.
and does anyone know or have an idea as to what rpm I could get by going up to the bigger carbs ?
advice on this would be good guys, as that extra 2.7mph might just do what I need.
here is a view of the venture on a 60hp carbs, its very restricted. .
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