Engine replacement

[MrWick]

I have a 1985 Merc 115hp inline 6 on a Checkmate boat that tips the scale at 750lbs not counting the gas.I am thinking about replascing this motor with a new 90hp Merc Classic(carburatered version),does any one have a guess if the 90hp will outperform the 85 115hp.I can turn 5500rpm's and about 50mph with the current setup,can I expect pretty close to the same thing with the new motor?Thanks for any info good or bad.

 

[Hooty]

Re: Engine replacement

I'm afraid if you replace the 115hp. with a 90hp., you're gonna be real disappointed. About 25hp. worth.<br /><br />c/6<br />Hooty

 

[LubeDude]

Re: Engine replacement

Yep, even though its old, those inline 6s were powerfull when runnin good, I would be surprised if you changed to a new 115 that you would out do it if its running good.

 

[DJ]

Re: Engine replacement

MrWick,<br /><br />THe 1985 115 you are considering replacing was rated at the prop, just as the new ones are.<br /><br />You're going to lose a little weight with the 90 but not 25+ horses worth.<br /><br />I suspect a new 115 would deliver equal, if not better performance.

 

[Chris1956]

Re: Engine replacement

Mr. Wick, Instead of replacing your 115HP with a 90HP motor, why not see if Clams Canino will sell you a rebuilt 150HP inline 6 powerhead, and take your 115HP in trade. This will give you some more power with the same weight.

 

[phatmanmike]

Re: Engine replacement

who is this clams canino chap, i have same motor....

 

[MrWick]

Re: Engine replacement

Thanks for the inputs.I don't need or want anymore horsepower as the boat is as fast as it can safely be with the motor thats on it now.I was looking for the same speed but a more reliable motor.I have replaced a stator,rectifier and upper end cap so far.It runs great right now so I will run it until I have more problems.Thanks again.

 

[Mercury140-I6]

Re: Engine replacement

IHO, you will not get a more reliable motor than the old inline 6 Merc's.<br /><br />Craig

 

[Clams Canino]

Re: Engine replacement

The propshaft rated 115 (that he has) is close enough to the older 150 that a trade/upgrade is not in order.<br /><br />Not only will his 115 blow away a later 90, but it will outcrank those 4 cylinder 115's. I'd bet my boat that my '88 115 would destroy one of those 2x4 125's in a 10 mile event.<br /><br />The 1985-1988 Merc 115 was the pinnicle of the Inline Six evolution... don't part with perfection, just fix it as stuff breaks.<br /><br />-W

 

[MrWick]

Re: Engine replacement

Sounds as if I need to keep what I have for the time being.The engine I have looks great for an 85 and ran great the last time out.I guess you all saved me some money.Thanks for your opinions.