'84 70hp any opinons

[ladano]

I'm looking at swapping power from a '84 115 merc to a '87 70 yamaha. The merc is just way to much for my '85 15' skeeter. Any problems with the 70hp? It has a rebuilt lower unit and fresh bearings in the top. The skeeter is rated for a 85hp, would it be to under powered with the 70? Thanx Dan

 

[ladano]

Re: '84 70hp any opinons

I guess there is none. Thanx

 

[Ray Neudecker]

Re: '84 70hp any opinons

Not an easy question, however there will not be much difference in the HP of either. At that time Yamaha rated the motor at the prop and Mercury at the flywheel. Kind of a toss up for performance.<br /> The 70hp has been a great engine but it is over 20 years old and previous use and maintence will have a lot to do with future service.

 

[ladano]

Re: '84 70hp any opinons

Thanx, I was told over on the merc forum that the '84 115 merc was rated at the prop also. The main thing was it was so heavy on my '15 skeeter. The 70hp I just got has a little tapping niose from the block, piston slap, wrist pin, or bearing, I'm not sure which. If I have to tear it down later, are the rods pressed on or they two piece on the crank? Any idea about how much parts would cost minus the machine work to overhaul? Thanx again. By the way I'm nearly stealing this motor, so I don't mind putting more money in it later.