Repowering a 242g. Are twin 115's Yamis enough?

[GulfCoast242G]

I have an 88 242G that i need to repower. l am replacing twin 140 Johnsons and am thinking about twin 115 Yamaha carbed 2 strokes from Edsmarinesuperstore.com(my second OB purchase from them) b/c the price is so good -$5500 ea.

The question is...is this going to be enough power considering the weight of twins. I know that a single 225 is pretty common on this boat.

Also, could a single be mounted on the twin bracket?

Any input would be appreciated.

Thanks

 

[Great Laker]

Go to Yamaha's web site and look up the performance numbers on another boat. Try and get as close to the weight of your rig as possible. Even though the hull designs are different and play a part in performance numbers, you'll get a basic idea.

 

[wahoo33417]

Great Laker has good advice. I know the Yamaha website has a performance test on a Grady 248 with twin 115 four strokes. I believe the 242 will have a little less deadrise being a "pre-Sea V hull", so you should do at least as well as the test.

Rob

Go to Yamaha's web site and look up the performance numbers on another boat. Try and get as close to the weight of your rig as possible. Even though the hull designs are different and play a part in performance numbers, you'll get a basic idea.

 

[GulfCoast242G]

Thanks for the advise! I just looked at the Performance Bulletin for F115's on a 247 advance CC @3500lbs and tested @5032lbs which is close to the offshore+. It showed 45mph at 6000rpm w/ a 13x19" prop.

Not sexy but I think it will work fine.

 

[Parthery]

Gulf coast...GW performance numbers for a 247 with F150s ran 48 mph...

I don't think it will be a speed demon with the F115s...and I would hate to sink the $$$ in and find out its underpowered.

 

[Montauk Explorer]

I don't think it will perform as well as if it were a single 225, due to the addl drag.

Think you need a little more punch.

 

[johny74]

They say if you have twins for example twin 150's that your boat really only has 150 hp, not 300hp. You will have more torque comming out of the hole to get on plane better. You also have to consider an extra 400 lbs on your ass of the boat depending what the outboard weights. ME personally I have a single 225hp and would rather have twin 150's just for safe keeping, but thats just me. My personal opionon is that its gonna be under powered, if your gonna do it, do it right and get the right engines or hold off for a bit to save the extra few dollars you need. I was looking into twin 130's honda four strokes and someone told me the same. Then I seen the price tag and said my 225 merc runs great why mess with it. :?