Mercury outboard question

[CAJUNLAWYER]

Have a 30 hp 2 stroke on the back of my boat and it is a wee bit underpowered for my boat. Specifically, the hole shot sucks-very difficult to get the boat up on plane even with a whale fin added. Engine is a 2002. Any outboard mechanics out there who know if the computer can be tweaked to bring it up to 40 hp power? The two engines appear to be identical so I am assuming that the difference in hp is due to a computer or some electronic governing. It's important as nobody makes a light enough 40hp today to replace it with.

 

[BillyMagg]

Turbo Time, you could get away with that Caj, try a new prop with LESS pitch, sounds like you need more RPM off the bottom end. Like I tell wifey on the bicycle when we're climbing a hill, shift down and spin, you gotta get that rpm up under load.....

you prolly need more boat and more motor, my little brothers 21 foot Triton with 225 XP will snap your nek a little!

 

[Steve in Vermont]

Caj, I had a 48 Evinrude 2 stroke on my 16 footer for 20 years and recently replaced it with a 40 Merc 4 stroke. Speed is about the same but the 4 stroke consumes much less fuel (it "sips" gas, not consumes it) and is a lot quieter.

 

[FishingPilot]

I bet there's more to it than just a computer change. Could be cylinder size, valve size, bore size or any number of internal block items. Just a few thousands can reap big benefits. I have the 60hp EFI 4 stroke and it's the same size as the 75 hp EFI 4 stroke but I doubt a computer tweak will get me up to 75hp.

As you are probably aware, prop pitch changes can give you better hole shots but suck the life out of the top end. Finding a happy balance can be expensive.

 

[Omenwolf]

It is simpler than a computer job. I believe the only difference in that model is the reeds in the carb. A easy way to check is look up the specs on both motors, if the bore is the same then it is most likely just carb stuff making the diff in HP. Change them out to a set from a 40hp and do like the guy above said and change the prop to a larger diameter and lower pitch. FYI I was an outboard tech for like 10 years, but it's been a while. Check with a Merc dealer in you hood.

 

[kozmic]

Caj, I helped a friend re-power his aluminum 16 footer over the winter. He bought a tiller-operated 40 hp 4 stroke Honda. It weighed a bit over 200 pounds. The old was a 30 hp Mariner and did weight a bit less as I recall.

He's had it out a bunch this spring and feels compelled to call me each time. He is blown away by the low end torque and mid range power. He's still breaking it in but so far, he's in love!

More hole shot power for your existing is typically a prop as stated. I put a fin on my last boat it helped with porpoising but I don't think it did too much to get me up on plane any quicker. As for remapping the motor brain, the manufacture's website or a dealer might be a starting point.

Orrrr, Maybe a nice, new 26' Regulator with twin 200 Mercury Verados might be in order....Your Suburban can tow it and it's got an enclosed head for Mrs. Lawyer!

 

[charlie sherrill]

Or come off that tight wallet some and buy a larger motor.

 

[Sprefix]

E-tec!! JMO......and an expensive one at that!!

 

[RBB Texas]

Prop?

If you lower the pitch of your prop, you will get better hole shots (at the expense of top end). Are you tucking the motor down when getting on the gas? Is the shaft length of the motor the right length for the transom? I'd try a different (lower) pitch prop first.

 

[Rugskipper]

1. Go on a diet.

2. Clean the old bourbon bottles out of the bilge.

3. Lock your gas tanks so the local constabulary can't pee in them.

Just tryin' to help.

 

[Lost Lake]

I was going to add:

Leave some of the beer at shore and come back and get it later...


.

 

[Rule3]

Most engines that have the same block but different HP is due to the carburetor, or fuel injection. Back in my boating craze a 9.9 and 15 HP were the same except for that. The 70 and 90 were the same. I do not know of that year engine if 30Hp jumped to a different block on the 40.

Last boat thread you had was a Whaler that was under powered what happened to that?

 

[gjamison]

E-tec!! JMO......and an expensive one at that!!

We have sold evinrudes for 30 years and the e-tec is far and away better then the merc!! I run a 250hp on my pontoon boat. Just an awesome motor!!!!!

 

[Rule3]

We have sold evinrudes for 30 years and the e-tec is far and away better then the merc!! I run a 250hp on my pontoon boat. Just an awesome motor!!!!!

Until you run them in Salt Water. Maybe since they are no longer OMC they may be better. The only engines you see down here are Yamaha and Mercs.

 

[cougar14]

What's your altitude?

In the Delta, my 85 hp Merc gets on plane fine. I took it to Reno once, it wouldn't plane period.

 

[gjamison]

My dad ran it in salt water for 6 months during the winter. Not one problem in the 4 years he's been doing it.

 

[Rule3]

My dad ran it in salt water for 6 months during the winter. Not one problem in the 4 years he's been doing it.

Remember the old OMC Sea Drives??

 

[model70hunter]

Remember the old OMC Sea Drives??

ARG, is that Captain Jacks dingy off the Black Pearl?

 

[model70hunter]

Have a 30 hp 2 stroke on the back of my boat and it is a wee bit underpowered for my boat. Specifically, the hole shot sucks-very difficult to get the boat up on plane even with a whale fin added. Engine is a 2002. Any outboard mechanics out there who know if the computer can be tweaked to bring it up to 40 hp power? The two engines appear to be identical so I am assuming that the difference in hp is due to a computer or some electronic governing. It's important as nobody makes a light enough 40hp today to replace it with.

My dad had a motor listed at 25 HP,it would run side by side with a 35 HP same brand motor and similar boat. I've done it. The dealer told us the only difference was the carb and the hp decal on the hood. He said Dad's probably had the wrong carb added during manufacturing. Ask the dealer if he can upgrade yours.

 

[Model 19 6"]

Nothing a good Evinrude or Johnson can't fix. My father said the Merc made a great black anchor.