Yamaha have new 130HP and 150HP options. I don't want to underpower it, nor weigh it down and shake it to bits with something too big. Any recommendations?

Would 130HP be sufficient, or really under powering it?

Cheers.

That's for the 6.2m commander? I'd be happy with a mid size engine.

Offshore as in game-fishing, or crossing blue water or longer passages with swell,  go for balanced horsepower …as in enough to maintain decent speed without as much weight in arse. Sure some might diagree but 150 hp four strokes are big motors and would be plenty on back of yours.

Very familiar with my own 16 ft stabi.. 60 fourstroke is plenty and very economical. Also have a mate 635 Bonito I fish on a bit has 150 Honda and goes real well. 

Don’t over power it.

OK long post, but has the experience, the reasons why and hows that I would have like to know when going thru this exercise... and assume others have the same thoughts/ questions

1st the Commander is 5.5m or 18' 2"

And they are an awesome salt water hulls at rest and on the plane, but like all hulls, cars, tractors , trucks to be any good for the end use, need the correct power.

 

With about 80L fuel under foot, guys ave around 90kg, fishing gear, 95L bin, bait burly bin, spare props anchors, battery etc andwith full bimini up.. Its always up.. comes in around the 1250kg total gross weight on water.

 We originally had 115 hp on the back fishing the Bottom end waikeke, Corro furth, Ahh ahhs etc

 Good but min  good power  WoT around the 40 mph cruise 32/34 mph around the 3900/ 4000 rpms.

Get in bit ave chop would cruise thru well, and run on an oilly rag. Chop get up a little more and then start to work the throttle and once that starts, gas goes up huge.

 Then where thinking about moving home, to West coast. Had time as next few months was hard out me doing complete reverbish the old old house and gardens etc. I had crossed bars many times over the yrs, and knew the 115 if something happens like wave climbs in front etc, or need to move quick, need that bottom end power.

Along with  crotch straps and actual life jackets..

I worked out (calculated) and also being on several other commanders and similar hulls that confirmed the equations around the min 130 to 140 hp would be the go.

Now came the 20" transom...and looking for a later model , good service record, 140hp with 20" leg.

 I was just tossing up to re build transom, but is still solid as, so thinking make up a simple jack plate or a full plate across the transom... cost to buy is stupid price.

Eventually a  V6 150 20" came up , ex lake , low hrs, serviced winterised from new.

 Loading the engine bay with the 115, Extra weight would set the stern down at anchor about 1/2 to 1" and nil diff once boat moving.

Swapped engines was a breeze, over and done in couple 3 or 4 hrs and 1 other person to hold transom bolts from inside... and engine hoist.

Result :

Get in serious chop on top of westcoast  swell or  a good westerly down the bottom of  Tamaki straight, white caps at near shoulder height, set throttle and chug home just on the plane and not falling off it... off Bottom end Waiheke  good stherly comes up and tide changes..

Have had 1 instance in the commander a wave stand up in front on the bar...got to it just as started to break, over, then there is always the next last swell of the set, big period, get to the next before started to break.....the 115 the 1st would have broken, have the power to power thru.. I dont know. I did the 2nd would have been on us, and bigger..

Couple instances of breaking bar waves coming in from the side going in.. yes the 115 would have done it fine, the 150  instance move lot heaps area and time around us.

Now cruise at the old cruise speed of 32/34 mph fuel consumption drops WELL over 10% better economy.. If travel at around 3900 rpms and 38/39 mph very similar as previous 115  32/34 mph economy....

WoT is around the 48/49 mph now as gone from a 80L (which is all that fits in the std commander 120L tank due to air vents) to a full 150L fuel tank... Take lighter guys, big fish bins out, 1/2 tank fuel goes around the 52 mph ...starts to chine walk a little... not my cuppa tea.

Down side, well only 1... With tthe 150, I have to say every time we take off, " Holding  on?"  And always turn and check everyone is.. there is always some 'hero' who wants to fall backwards.. Its put into gear, boat moving, move throttle gently forward a little... wait to go over the bow wake start trim up, and now at cruise speed.. no throttle adjustment.

It is my understanding that these boats in general, made around the 70s /80s where rated to around 140/150 hp..

So 2 stroke 115hp good for general harbour stuff.  4 stroke 120/130 will do your bars , good chop etc.

The 115 and the 150 are/ where both correct height within 1/2 adjustment notch (bars on drops slightly) propped to correct WoT and Cruise slips, and pitch..

 

If I understand it sounds like you're saying 130HP 4 stroke should be fine?

Looks like the 130HP Yamaha is the same 1832CC as the 115HP engine, but gets more HP out of it.

Rather not just "fine" but very nicely powered..

 Which poses the question.. is the hull a Sea nymph 6.2 hustler or a 5.5 Commander?

Also of note is the issue of 20" transom mentioned by the poster.. which is the Commander. The 6.2 is 25" on pod.

 If the hull is the longer and heavier 6.2 Sea Nymph, then I would be suggesting going at least 175 hp, preferably 200 for bars

Should I specifically ask for a stainless steel prop? I hadn't really thought about it. Presumably these are the best?

Displacement is a good indicator of Torque and Torque is what you need for acceleration and bar crossings etc. 

So your best options are the 3 litre v6 Mercury, 2.8 litre 150 Yamaha, or the 2.3 litre 150 HP Honda as a minimum. 

Here's the boat:

Definatly 5.5 or 18'6" Commander

This was my first boat

Depending on how cooperative the dealer with engine is ..and assuming they dont exchange props willingly..

Stainless are expensive...if not close enough, and need a 2nd you are up for bit either side of a grand.

 Alloy is  far cheaper.

 As to hole shot.. well powered , like WoT speed, does it really matter? If have good comfortable climb over the bow wave at part throttle  do you need to be able to throw ppl back off their feet?

On the surface that is the most logical way to go. In practice doesnt work that way.

I have been watching markets for couple yrs now to do something like that.

Assuming ones current 'older' boat is solid.

Everything around that price is either older ( thinner hull alloys , suspect hull issues, and /or min to under powered, or high hrs sort stuff.

 Get into the $45/65K and one is starting to talk, but even then so many are still min or underpowered  compared to a 130/ 150 hp on the back of a fully loaded Commander.

 

Yeak PJC

 These are all pionts we looked at and still are for a few yrs now.

It depends how money flush on is..

 We are not..hence going 2nd hand low hrs , maintained 20" that took a couple yrs to turn up.

We where at the stage of increasing transom as getting close to moving west and 25" 140s where popping up every now and then... 2S dropping in price (thats sale price not asking price) with 4S coming in.

Capital cost of the new or newer 4S engine against the older cost of fuel for 2 S.

Then throw in sale value maybe another 10yrs down the line.

 A balance of the maths sorta..

These numbers maybe of interest to some.

New wasnt an option for us.

Ended up buy the 2S  150 , 9K  run it for 6months or so then sold the2S 115 for 7K .. fitting ourselves so the upgrade was 2K plus sealant etc... and well propped extra economy (so long as cruise at old speed)

Have put thru 3X 20L drums oil approx $340 each @ 1L per 48L fuel (which would use anyway) equates to around just over 2800L ...

yeah we do and have done lot fishing..

With around 12+ % increase in economy ..

 think my of the top of head maths is  close..

That equates to about $100 less oil

And fuel at older $2:20L around $600.

 So cost engine swap less 700 still about $1200 todate cost engine upgrade

 I have noticed the market with these older 'Commander' ranger hulls good condition, may need a coat paint to hide the odd chip here and there, sell around the 10 to 14K with a good post 2000 engine and trailer... even if have a later model  4S

And the ones with later model 4S list for long times and dont sell at  the " what the boat owes me" prices.

That is a a good point as well...

We have never (over 50yrs) brought anything paying cash, other than mortgages on previous homes.

Rather than pay interest even worse compound interest, we put what we would do aside, plus the disposable income used to eventually buy what ever ..

 So cant comment on cost deposites etc..but what you are saying sounds right for those work do that stuff.

End of the day it does come back to bit of caught between the ocean and deep blue sea.. catch 22

 

Good question. The answer has two parts:

1. Yamaha are offering good financing terms for the new engine, and I don't have $25k in cash to hand. I'm unlikely to get as good financing on another boat.

2. The current steering and engine are completely munted. Who will buy a boat they can't even take on the water for a test drive? I suspect I'd be doing well to get $10k, and could get a great deal less.

The current hull is in good condition, and I think with a new engine and steering it will be something to last for years.

If anyone wants to offer $10k for the boat as-is send me a message please 

Yamaha approved 1.95% financing so might go for the new 130HP engine. Since it's 5.5m my understanding is that should be okay.

The hull is in good condition, although of course that's for its age.

The trailer was built specifically for it brand new in 2020 so no issues with that part at least.

Is any boat not a money pit? :-)