Small upgrade

[thatkidhugo]

I have been running a 1976 merc 7.5hp on my 14ft semi v and I have a guy who will trade me a 1992 merc 9.9hp converted into a 15hp with a bit of extra cash from my pocket.

To be honest the 7.5hp is very sluggish with 2 people in the boat + gear and I need a bit more power.

Do you guys think it will be worth my money for the upgrade? Will I see a significant amount of speed increase? The 15hp also has a hydrofoil stabilizer.

Also, I have heard that the older mercs (pre 1985?) dont offer full hp to the prop. What I mean is, a rated 7.5hp will only be about 5-5.5hp to the prop. Is this true? If so then I think I will have to jump on the deal.

 

[shawnfish]

I have been running a 1976 merc 7.5hp on my 14ft semi v and I have a guy who will trade me a 1992 merc 9.9hp converted into a 15hp with a bit of extra cash from my pocket.

To be honest the 7.5hp is very sluggish with 2 people in the boat + gear and I need a bit more power.

Do you guys think it will be worth my money for the upgrade? Will I see a significant amount of speed increase? The 15hp also has a hydrofoil stabilizer.

Also, I have heard that the older mercs (pre 1985?) dont offer full hp to the prop. What I mean is, a rated 7.5hp will only be about 5-5.5hp to the prop. Is this true? If so then I think I will have to jump on the deal.

around 1985 or 6 all outboards started rating their HP at the prop instead of at the flywheel. and yes its true, your 7.5 is probally only pushing about 5hp. how did he convert the 9.9 into a 15hp??? if its really 15hp it should give you about triple the hp you have now....oh and im not sure the hydrofoil on that small of a motor really does anything except for maybe help you plane quicker, but i could be wrong.......

 

[JMichael]

I agree with shawn. I'd remove the whale tail and look in to getting a different prop if it doesn't get on plane fast enough. Depending on how much money you have to hand over, I think you will be pleasantly surprised with the extra hp.