Ruminator
02-19-2004, 01:21 AM
I realize that in terms of horsepower, my 70hp. is w-a-y down the scale from most of you. But it is the max that my boat is rated for, and so..... all I have to work with.
It's a newer motor being a '98 and put up thru the winters up here. What I need help with is getting more top end speed out of it. It is mounted on a very light-weight aluminum hull. (700 lbs.) Total pkg. weight is around 1500 lbs. for any given trip.
I get around 32 mph. @ 5600 - 5700 rpm.
I already have all the weight in the extreme back of the boat (three batteries) that can be moved. There is nothing else in the boat except two anchors that total 30 lbs. other than myself and my wife. So redistributing weight to the rear has already been done unless I have my wife straddle the outboard and dangle her feet in the water to the sides of it. :p :p Yea, she'd go for that!! :D :D :D
I'd like to know if there are mods I can do to increase the hp. to gain more speed at the top end. Carbs, jetting, heads, etc.
Did OMC use the same engine block for several hp. rated engines with other changes to give the different horsepowers?
I know they did with their smaller 9.9 and 15 hp. engines.( diff. carbs)
The motor came with a factory aluminum prop - 14 x 17. I plan to first change this to a SS one.
Thanks,
Jim
It's a newer motor being a '98 and put up thru the winters up here. What I need help with is getting more top end speed out of it. It is mounted on a very light-weight aluminum hull. (700 lbs.) Total pkg. weight is around 1500 lbs. for any given trip.
I get around 32 mph. @ 5600 - 5700 rpm.
I already have all the weight in the extreme back of the boat (three batteries) that can be moved. There is nothing else in the boat except two anchors that total 30 lbs. other than myself and my wife. So redistributing weight to the rear has already been done unless I have my wife straddle the outboard and dangle her feet in the water to the sides of it. :p :p Yea, she'd go for that!! :D :D :D
I'd like to know if there are mods I can do to increase the hp. to gain more speed at the top end. Carbs, jetting, heads, etc.
Did OMC use the same engine block for several hp. rated engines with other changes to give the different horsepowers?
I know they did with their smaller 9.9 and 15 hp. engines.( diff. carbs)
The motor came with a factory aluminum prop - 14 x 17. I plan to first change this to a SS one.
Thanks,
Jim