90hp or 115hp?

[Reel Kahuna]

Just bought a Yukon Delta 27' trailerable houseboat that weighs about 2500lbs but did not come with an outboard motor. I've narrowed it down between 2017 90LA or a 115LB about $1000 price difference. Will use it to cruise the Delta so speed is not important. Looking for the best bang for the buck. Comments?

[panasonic]

For a extra $1000 dollars for 25 more HP...I would go for that. Better to have a bit more juice than needed...then not enough. By the time the women got everything from the land house put aboard it...you just might need that extra 25 hp just to get her to move..lol

[Jason2tpa]

You've got a heavy and wide berth vessel. So I'm thinking the bang for the buck your looking for isn't so much with the hp of an engine, but the torque its capable of. I'm not familiar with the calculation required to determine torque at specific rpm. Perhaps someone else can chime in with that info.

The specs for the F90 and F115 are practically identical...both are I4, same compression, bore and stroke, and same compression ratio. The F115 weighs 24lbs more than the F90. Since speed is not a factor in your decision, seems like your not going to experience $1000 bucks worth of bang for your buck with the F115.

[zenoahphobic]

You've got a heavy and wide berth vessel. So I'm thinking the bang for the buck your looking for isn't so much with the hp of an engine, but the torque its capable of. I'm not familiar with the calculation required to determine torque at specific rpm. Perhaps someone else can chime in with that info.

The specs for the F90 and F115 are practically identical...both are I4, same compression, bore and stroke, and same compression ratio. The F115 weighs 24lbs more than the F90. Since speed is not a factor in your decision, seems like your not going to experience $1000 bucks worth of bang for your buck with the F115.

I think you hit the nail on the head, with a large barge you are unlikely to realise any increase in performance, as often low end torque is traded for higher revving horsepower, that means you will have to rev the engine more and that converted to extra speed maybe achievable with a lower pitch prop. Seems not what you want, a busier motor?

[99yam40]

I would think a larger prop could be used with more HP and a reduced RPM could get the same cruising speed using less fuel.
maybe look at the performance bulletins to see what they say

does this have a max HP rating on it

[panasonic]

Does Yamaha publish HP/Torque graphs ?

[Reel Kahuna]

The specs for the F90 and F115 are practically identical...both are I4, same compression, bore and stroke, and same compression ratio. The F115 weighs 24lbs more than the F90. Since speed is not a factor in your decision, seems like your not going to experience $1000 bucks worth of bang for your buck with the F115.

I think you hit the nail on the head,...

This makes a lot of sense and has me pointed at the F90.

Thx guys.

[fairdeal]

The specs for the F90 and F115 are practically identical...both are I4, same compression, bore and stroke, and same compression ratio. The F115 weighs 24lbs more than the F90.

I'm really curious as to what those extra 24 pounds are - anyone know?

[TownsendsFJR1300]

I'm really curious as to what those extra 24 pounds are - anyone know?

I'd suspect a heavier crank, cams, mounting brackets, T&T, slightly larger block, etc.

20 lbs isn't much when bumping up an engines HP keeping it dependable.

I'd personally go for the 115, better plenty of power, vs not enough.

[Jason2tpa]

I'm really curious as to what those extra 24 pounds are - anyone know?

24lbs of internal anodes to equate the $1000 price difference

[Reel Kahuna]

Well I was ready to drop the hammer on buying the F90LB but that dealer wouldn't offer the Y.E.S unless I paid full retail so decided to call one more Yamaha dealer.

He offered a F115LB at dealer sheet cost with Y.E.S and was only $800 more than the F90LB that the other dealer offered.
Needless to say I bought the F115.

It certainly pays to shop around .

[almetelo]

I'm really curious as to what those extra 24 pounds are - anyone know?

Haven´t had a look on the parts manual but my local Yamaha dealer when was introduced the F100F (latest model) as latest F90 said that while F100F have 8 valves the F115/F130 have 16 valves so diferent head...
Same bore on the block but the pistons are diferent.

Thats all I know but for sure other diferences that will not affect much on the weight.