2015 yamaha 75hp too a 115hp

[leecrosby813]

is there any way to change a 75hp outboard 4stroke to a 115hp..??

 

[99yam40]

compare part numbers on the motors to see if any are the same.
75 to 90 maybe, but I do not think 75 to 115 would be possible unless you did some major modifications and program changing.
turbos or blowers too

check with some racing forums maybe to see what they say

 

[boscoe99]

Nitrous oxide or a super charger.

 

[jbcurt00]

is there any way to change a 75hp outboard 4stroke to a 115hp..??

Checkbook/credit card at your local marine dealer.....

 

[99yam40]

Nitrous oxide or a super charger.

yep, takes more fuel and something to oxidize that extra fuel, (more air or nitrous) and then it all has to exit the motor properly too.
not easy to throw a set of tuned headers on an outboard to help it breath.

 

[ahicks]

Not from a practical standpoint. The ONLY possibility, and I'm not REAL sure if it would even work, would be to find a 115 power head (complete w/intake and carbs/fuel injection) and swap it with your 75.

 

[boscoe99]

Not from a practical standpoint. The ONLY possibility, and I'm not REAL sure if it would even work, would be to find a 115 power head (complete w/intake and carbs/fuel injection) and swap it with your 75.

Won't fit.

 

[ahicks]

Won't fit.

Would you like to be a little more specific?

Engines are the same weight, share bore and stoke dims (I think?), so I thought the blocks might be interchangeable? No?

 

[99yam40]

Would you like to be a little more specific?

Engines are the same weight, share bore and stoke dims (I think?), so I thought the blocks might be interchangeable? No?

are they the same part number, they would need to be for all the parts to fit

 

[boscoe99]

Would you like to be a little more specific?

Engines are the same weight, share bore and stoke dims (I think?), so I thought the blocks might be interchangeable? No?

Blocks are not the same. The exhaust guides that the blocks mount on are not the same.

 

[ahicks]

Could it be that older models used the same displacement for the 75/90/115's?

 

[roscoe]

is there any way to change a 75hp outboard 4stroke to a 115hp..??

Talk to a witch, genie, or magic fairy.

 

[boscoe99]

Could it be that older models used the same displacement for the 75/90/115's?

No.

 

[jimmbo]

is there any way to change a 75hp outboard 4stroke to a 115hp..??

Yes, unbolt the 75 and replace it with a 115.

Even if the Displacement is the Same, there will plenty of Differences to make the additional HP.
Adding HP at the Top, pretty much results in a Drop in Low Rpm Torque, so even though the Boat would have more HP, the holeshot will be slower.

 

[boscoe99]

Yes, unbolt the 75 and replace it with a 115.

Even if the Displacement is the Same, there will plenty of Differences to make the additional HP.
Adding HP at the Top, pretty much results in a Drop in Low Rpm Torque, so even though the Boat would have more HP, the holeshot will be slower.

Are you saying that the torque of an F115 at say 2000 RPM will be less than the torque of an F75 at 2000 RPM?

 

[ahicks]

No.

Thinking I was going crazy (again), I looked for myself, and I see that Yamaha is saying the 4 stroke 75/90/115 weight/bore/stroke/displacement ARE the same on this web site. Scroll down to "Specs and Compare"

115-75 HP 1.8L I-4 Outboard Motors - Yamaha Outboards

The 1.8L I-4 F115 horsepower In-Line Four Yamaha outboard is a mid-range four-stroke outboard that is perfect for your family boat and watersports towing.

yamahaoutboards.com

This leaves me wondering about the info you were sharing? Not looking for a pissing match, just trying to figure out what seems to be quite a discrepancy.

 

[jimmbo]

Are you saying that the torque of an F115 at say 2000 RPM will be less than the torque of an F75 at 2000 RPM?

If the same displacement is used in both motors, quite likely.

 

[boscoe99]

Thinking I was going crazy (again), I looked for myself, and I see that Yamaha is saying the 4 stroke 75/90/115 weight/bore/stroke/displacement ARE the same on this web site. Scroll down to "Specs and Compare"

115-75 HP 1.8L I-4 Outboard Motors - Yamaha Outboards

The 1.8L I-4 F115 horsepower In-Line Four Yamaha outboard is a mid-range four-stroke outboard that is perfect for your family boat and watersports towing.

yamahaoutboards.com

This leaves me wondering about the info you were sharing? Not looking for a pissing match, just trying to figure out what seems to be quite a discrepancy.

You are looking at the very latest 1.8 liter models.

OP asked about the 2015 models.