can it be done !!!! 18' CC Cobia w/70hp

[al365s]

My name is Alex, i'm new to iboat.

Just got 18' CC cobia it's a 1979. Would like to use the motor from another boat, 70hp evinrude not sure if it will get on plane.

Do you think this small motor can be proped enough or not?

1,775 lbs hull
275 lbs motor
100 lbs trolling motorgear
360 lbs batt., Fuel, gear
500 lbs 2 people

3,010 lbs total

Hoping you can help,
Alex

 

[SparkieBoat]

Re: can it be done !!!! 18' CC Cobia w/70hp

probably get on a plane if you prop it right..maybe only 25 mph..just my guess..make sure you prop it right..if you live anywhere near Savannah I have a 1995 115 that I may trade if that is a late model 70

 

[Texasmark]

Re: can it be done !!!! 18' CC Cobia w/70hp

Agree with SparkieBoat and maybe he has a good engine to trade if you are up to that. The 115 will do much better and could move you up to the 30-35 mph area which is a lot more enjoyable......70 isn't much on a 3000 boat! Also a tach is a must for what you are attempting and prop for top end of the recommended operating range at WOT with your normal load. You won't have much pitch on that engine pushing that load. I had a 125 Johnson on an 18' tri-hull years ago (probably equivalent to today's 115 with prop rating) and it would push the boat to 40 with either a 17 or 19p SS OMC prop forget which. But that combo would also easily pop up 1 200# slalom with the family aboard or a pair of kids.

HTH

Mark