Crunching numbers without head hurt
A given weight (mass) with a given force will move at a given speed.. bit simplistic but basic physics.
Therefore a 130 with manufactures max WOT operating range of 5000 to 6000 rpms being reached @ 5500 rpms @ 55km works out to around 1850kg .. 1900 kgs gross weight on the water at best trim, constant adjusted for modern post mid 60s + trailer boats.
This also assumes the engine is currently at correct height at cruise and at best trim for above and everything below.Current Setup: With a pitch of 16 with that prop grip design.. more cupping..
you have a slip of 18% at WoT.. for a
general use boat well powered should have around 5% @ around mid way or slightly below Manufacturer recommended WoT operating spec... Which you are at.
Ideally you should have a smaller pitch...14/15" with a similar GRIP prop which would give around 7/ 12% slip.
In essence, baed on the boats weight
you are well under powered.. this effects cruise speeds, economy at reasonable cruise speeds, and far more serious how he hull performs in chop, over wakes ,bar crossing etc.
Any change of prop beyond what you have, will in economy only.. slightly.. and will not be worth the capital investment
OK lets crunch numbers on a 225 hp
WoT @ 1900 kg (above calc weight + bit more for bigger engine) crunches to around 40 knts, 45 mph 72kmh
Prop:
WoT
Crunching numbers with diff gear box ratio in the 225 a suitable prop would be around 14 1/4" diameter and a pitch of 17" to give WoT slip of 5%
Cruise: 3800 rpms @ 12/ 15% slip will cruise around 32/ 33 mph 28 knts/ 53 kmh.
Economy It will do so at very close to your current 4000/ 4200 rpms cruise speed.. very likely to be around 10% + less on distance per Litre fuel basis.
The performance...Always make sure everyone is holding on.. trim down, move throttle forward a little.. let it go, as comes up on plain , trim up and you will be near to a 3500/ 3700 rpms cruise speed... AND still not touched the throttle.
Flat water fast cruise, got to cross a largish wake...
currently would back off throttle, trim down a little, line u and cross, bit uncomfortable (???) yes?
225 or well powered.. fast cruise, line up, trim down a bit, no change of throttle, cross more comfortable or as comfortable as before, at far greater speed.
Get into bad chop on way home, before trouble holding speed, adjusting throttle, trim as sets change, a quite a few big bow crashes etc yes?
Well powered/ 225 .. set trim set throttle, faster speed, and MAYBE 1 bow crash.. you now have power in reserve at any given low to high mid range rpms to be able to hit a wave/ whatever and not slow down or stall.
225 hp Thats
getting into over powered.... just means dont play hero, always warn and check a crew is not playing hero.. when taking off. No different to diving a lower end muscle car on the roads...
What WILL happen. If you are currently ' happy with current cruise speeds etc, and continue t travel at them you will use FAR less than current fuel levels.
So in practice, you WILL travel at far faster cruise speeds
1/ Engine noise will be far less
2/ ride far smoother
3/ use same amount as fuel.
4/ will travel even faster still far quieter and smoother once filling up after a couple trips and find only see another 5 or 7L fuel being used for the day fishing trip.
5/ towing , will use far less fuel, engine will not longer working with huge amounts of reserve power.
And yes this is all one from crunching numbers
Final Prop selection on 225.
Take data from what ever prop is on the boat.. so long reaches in manufacture WoT range 130/ 225 honda 5000/6000 rpms... Crunch numbers and then select prop IF the capital investment justifies it... or wait on trade me or what you want to turn u for $ 100/150.
End Of the day?
Would I do the swap? Hell yeah
I did.. from a min powered (you are under powered) 115 well proped on a 1200kg gross weight on water commander to a 150 hp.. resulting in very similar numbers (crunching and in practice) to what you are looking at
I hope this answers your questions and those that would be asking
Cheers
Steps
PS Im looking for someone to turn the Java based calculators I have nearly finished creating to make the number crunching simple into android/ apple apps
Creating them .. THATS head hurt when coding by the seat of the pants .. and havnt even looked at how to make a smart phone app yet
PS the 130 would be every suitable on the back of a 5.0/ 5.5m 1050/ 1250 tops alloy/ glass cabin boat....