New motor required 150 V 175

[Streaker]

Hi
seeking some input from the experienced ones. Looks as though we need to replace the outboard on the Scam : - 6.5 metre plate boat Masters Marine design, weighs in on the water at about 1.5 tonne.
The onwer is looking at replacing the current motor with a 150 suzzi and I have suggested that a 175 be considered.
We will need to consider the cost difference between these 2 motors, the running cost litres per hours 5.5 V 5.8 at 4500 RPM.
My thoughts are: - a 175 would require less RPM to travel at the same speed and the extra power would be available when required.
Any and all responses will be appreciated.
Wayne

[Vitamin Sea]

Hi

What is the max the boat is rated to? I would always go max hp if given the choice and have the $$$

Cheers

[Streaker]

I understand that the manufacturer has indicated 175 hp, but as the boat was built 12 years ago there is no compliance plate fitted.
Wayne

[doublexl]

The 175 has variable valve timing and will be better on fuel.

[cormorant]

What is the current motor, 2 stroke , 4 stroke year , weight , brand and it's performance? Is thw owner happy with that performance- doe she travel cruise or wring it's neck? Ha sthat motor lasted 12 years and what hours?

Why not rebuild the current motor?

[BigE]

New 150 merc could be worth a look. big cube lazy motor.

[fisho8]

Price up the 150 Merc to the 175 zuk either should push that boat along quite nicely. I am running a 175 opti on the back of my Clearwater 2100 walkaround it get's along at 4000rpm doing 30mph with no hassles at all that extra 25hp makes quite a differance.

[Greg P]

Wayne I have the DF150 on the 6m Fisher and more than happy with it still after 550 hrs. It has been faultless but If I did repower it would be with a DF175 or even a 200. I steered away from the VVT back in 07 but probably should have pulled the trigger. Still the DF150 is good for 37.7 knots and will cruise all day 20-21 knots @ 3900/4000 for 1nm per litre offshore. Even better with the tide.

I don't believe the 175 would be better on fuel on my boat, if anything it would maybe use more with the increase in torque curve in low to mid rpm but would probably be quicker out of the blocks but not sure if I the difference would be huge. The VVT is just adjusting the vale timing/curves and other than that they are identical but not sure if the ECM is mapped different. At the end of the day it needs to hit a certain rpm with a certain pitch prop they just go about getting there different. If you got a good deal on a DF150 then I wouldn't walk away from it.

The AMM will be a well built boat so don't spare the ponies.

[Streaker]

Thanks for your input on this. the owner is looking at the 175, not much change out of $21000.
Wayne

[Dan5]

Just throw a spanner in the works............have you had a look at the 225yamaha?.......a mate just upgraded from a 150yammy to a 225 on his 609 Stabi........it cost him a few hundred to have the hull re-rated but by all accounts has made a significant difference to his speed and economy compared to the 150.


Dan

[John_R]

The Merc 150 is 165hp and the Suzuki 175 is 172 - 7hp difference, while the Merc is about 3 grand cheaper and 10 kgs lighter. The Suzuki is 2.8L while the Merc is 3L - both 4 cyl.

If the AMM was ok with a 150, I have an Opti 150 for sale - so I can upgrade to the Merc 150 4 stroke on my Noble 6.2.

[Smithy]

Dan, is that from the F150 to the new 4.2 litre 225?

Hard call. I was in the same predicement three or so years ago. At the end of the day the Yammie deal was the best for me through Brisbane Yamaha. They also threw in the electronic gauges with fuel flow etc. Suzuki didn't sharpen the pencil at the right time and Honda weren't in the equation price wise other than offering me full 5 year warranty on a commercial vessel when everyone else was 1 year. The 150 Merc wasn't in the equation at that time. It is worthy of consideration. Same for the F150 Yammie. It was a good motor and at 2.6 litres capacity I never ran out of horsepower on Wide Bay Bar etc. when I really wanted some power.

Like all these discussions, at the end of the day it will come down to your deal and what dealer you are most comfortable with.

[ranga7]

Just imported a 175 from the states and got plenty of change from $21000. $6000 in change once fitted.

Thanks for your input on this. the owner is looking at the 175, not much change out of $21000.
Wayne

[Dan5]

Dan, is that from the F150 to the new 4.2 litre 225?

Hard call. I was in the same predicement three or so years ago. At the end of the day the Yammie deal was the best for me through Brisbane Yamaha. They also threw in the electronic gauges with fuel flow etc. Suzuki didn't sharpen the pencil at the right time and Honda weren't in the equation price wise other than offering me full 5 year warranty on a commercial vessel when everyone else was 1 year. The 150 Merc wasn't in the equation at that time. It is worthy of consideration. Same for the F150 Yammie. It was a good motor and at 2.6 litres capacity I never ran out of horsepower on Wide Bay Bar etc. when I really wanted some power.

Like all these discussions, at the end of the day it will come down to your deal and what dealer you are most comfortable with.

I think so mate,it was fitted about 3 months ago so if the current engine is 4.2ltr then that would be it..........apparently it was lighter than the 200Yammy?..........The boat is heavily modified with over 750ltrs of fuel and 150ltrs of water,hard canopy at the rear built in cupboards etc etc......the little 150 did'nt cut it any more hence the HP upgrade.

Dan

[cormorant]

The Merc 150 is 165hp and the Suzuki 175 is 172 - 7hp difference, while the Merc is about 3 grand cheaper and 10 kgs lighter. The Suzuki is 2.8L while the Merc is 3L - both 4 cyl.

If the AMM was ok with a 150, I have an Opti 150 for sale - so I can upgrade to the Merc 150 4 stroke on my Noble 6.2.

Those numbers are on premium fuel in controlled conditions so in real life on the back of your boat I would be interested. Those numbers come off the labels on the transom brackets or dealer advertising?

I'll say this till I'm red in the face. peak HP is a bullcrap number unless you are racing in a straight line WOT. You need to have a good look at the torque curve on motors and at what revs/ fuel ecconomy they may good cruising power. A good prop and setup will make the same diff at 10hp in that size motor

The above is why some motors seem so tractable and so easy to drive on a boat. Not that they produce the best peak HP but because they have the right torque at the right revs with the right prop to keep the boat moving. Some motors in each catagory have this sweet spot. Others have their reputation as thier wide torque band mans they are suitable fro a wide range of boats of different set ups and weights and can make a average boat a pleasure as a package.


So at 3500 - 4500 rpm what hp are the existing and proposed motors making.

Bring on the dyno tests of run in motors I say and load the dyno with typical boat weight and prop profile so you can see how all the fancy electronics work on a motor .