Hydrofoil or Trim Tabs??

[Texasmark]

Questions:
1. How do you "hole shoot"????? Angle of the engine vs transom, what do you do with the throttle when executing?

2. What are the RPMs when you are up and running and have trimmed out for maximum speed with your normal load and persons gear in normal position in the boat?

3. What is the prop you are using....material, pitch, name if stamped on the prop? You may have to remove it from the engine to get some of the information as it is sometimes stamped on the hub not on the outer surface.

 

[racerone]

The performance is so bad that it almost sounds like the trailer is still strapped under this boat.-----Sorry I have seen the cartoons.------Something is seriously wrong with this boat or motor !----Hurry to a friendly boat shop / dealer.

 

[dwco5051]

Sounds like it may be a simple as a prop change since it has done it since new. Our local dealer dealer is closed til the third week in March. I know if I gave him a call he could tell me close to what pitch you should be using.

 

[Starcraft5834]

agreed, that boat should fly 45+, your probably over propped...

 

[JimS123]

I wouldn't suggest anything until you know what your max speed and max rpm is when loaded normally.
Also with your 3rd person, where are they sitting?
While you might be able to slap a hydrofoil on and be good, you might still be under your max rpm and straining the engine.

You are correct. See the step by step procedure in post #14. That'll get optimum performance, provided that the engine has no underlying problem.

Foils on I/0s can be iffy because the outdrive has a fixed position. However, I have never seen an outboard boat that didn't see a huge improvement with a fin. (except maybe a little tinny with a 9.9 tiller)

Also, from what I see, there are few package deals that are set up optimally from the factory. Just slap them together and let the customer have it. Dealer knowledge is even worse. The Grandpa that started the business 60 years ago knew everything, but now the Grandson is in charge and he just wants to sell boats.

 

[racerone]

If it has a 21 " or 23 " pitch prop on it now it needs a 17" pitch.------You are so right about the grandpa / grandson comparison.-----

 

[Popeye251]

@Popeye251 - Am I catching this correctly that you bought the boat new from a dealer? And the boat with three people and gear on board (but not overweight above MAX Capacity) won't do over 13MPH?

Because if I've got that right, it's time to bring the dealer into the equation (I think). That boat is rated for a MAX HP of 150, but it's regularly sold with 115HP. I don't know what the performance difference is between the two ('cuz 115 is at the bottom end of the HP you would want by math), it shouldn't keep it from planing.

No that is not it.. with 3 people and gear it struggles to get up on plane at times. As stated a few times now in the thread, it will run about 40 once up, it is getting it up that it struggles with especially if there is wind.. maybe it is something mechanical I don't know but it seems to run fine.. we (meaning myself and the dealer) are still trying to troubleshoot why the tach is off so I have no idea what rpms I'm turning, but it sounds to me like it is about right.

 

[skuhleman]

No that is not it.. with 3 people and gear it struggles to get up on plane at times. As stated a few times now in the thread, it will run about 40 once up, it is getting it up that it struggles with especially if there is wind.. maybe it is something mechanical I don't know but it seems to run fine.. we (meaning myself and the dealer) are still trying to troubleshoot why the tach is off so I have no idea what rpms I'm turning, but it sounds to me like it is about right.

Are you sure the tach is off?
Also what pitch are you currently running?
We are trying to make sure you are propped correctly before putting bandaid fixes on it.

 

[JimS123]

G3 isn't exactly a stellar boat. It wasn't set up at the factory for everyday use and your dealer doesn't have a clue.

The dealer can access the engine computer to see if the tach is not correct.

Not that it isn't possible but its likely that the engine is running fine. You are overloading the boat and need to get the correct prop for your everyday usage. Even under powered boats can be made to run well with the correct prop. Yours is not underpowered, per se', but its not at the top end of the power curve.

All your data indicates the wrong prop. Run it at WOT with your normal load and get the RPM / Speed data. Its really not rocket science.

 

[southkogs]

Maybe I've missed it somewhere in the topic: how is the motor trimmed? I'm assuming you can trim the outboard before you blast off? (That doesn't feel like the answer, but it doesn't hurt to ask)

 

[JimS123]

Maybe I've missed it somewhere in the topic: how is the motor trimmed? I'm assuming you can trim the outboard before you blast off? (That doesn't feel like the answer, but it doesn't hurt to ask)

That's not rocket science either. Since the dealer is involved he must have asked appropriate questions....or am I being totally naive?

 

[Sea Rider]

Without knowing achieved wot rpm with 2 up once on plane won't know if motor is revving healthy. Is there a tach installed ? If motor runs healthy throughtout the entire rpm range, the combo could be drinking a cocktail of the following : motor is over propped, baddly trimed, badly transom height matched, badly deck load distributed. Check if having already a spun hub or on its way to become fully so.

A motor running middle to max wot rpm factory stated with all those mentioned points dialed spot on will jump on plane easily specially if lightly loaded as described...

Happy Boating​

 

[QBhoy]

You’ll lose top end if you’re over propped for sure. Most engines these days make their peak power near or at the top of the rpm range. So often dropping in pitch to allow the engine to make its power well, will see a gain in top end. Not to mention that most props these days...the faster they are turning, the more lift you’ll get out the water, resulting in more top end.

 

[racerone]

Fact------A test I did myself.----Same 16' ski boat , same afternoon ,same tilt pin hole , same driver, same sst style props.----A 1970 model 115 Evinrude no power trim. -------19" pitch , great acceleration , maximum RPM 5800 , boat speed 54 mph.-----Then a 21" pitch , good acceleration, max RPM 5300 , boat speed 54 MPH.-----Then 23" pitch , lousy acceleration , max RPM 4800 , boat speed 54 MPH.

 

[QBhoy]

Fact------A test I did myself.----Same 16' ski boat , same afternoon ,same tilt pin hole , same driver, same sst style props.----A 1970 model 115 Evinrude no power trim. -------19" pitch , great acceleration , maximum RPM 5800 , boat speed 54 mph.-----Then a 21" pitch , good acceleration, max RPM 5300 , boat speed 54 MPH.-----Then 23" pitch , lousy acceleration , max RPM 4800 , boat speed 54 MPH.

Bloody quick boat, by the sounds of it ! Fair play.
You’re defo correct.
On one of my boats...run a 21” on it, at 5100 ish rpm it will see 67 mph gps. Throw a 23” on it. Most times it won’t be quicker or slower and a nightmare to plane if a few onboard. And a total dog at cruising speed and lugging.

 

[racerone]

Working on an ---Action Marine 17 --Look for them on U-tube.---When spring comes again.----All wood taken out of transom and floor , and replaced with composite material.-----With 150 HP at the propshaft it will be very quick I expect.

 

[QBhoy]

Working on an ---Action Marine 17 --Look for them on U-tube.---When spring comes again.----All wood taken out of transom and floor , and replaced with composite material.-----With 150 HP at the propshaft it will be very quick I expect.

Sounds tasty !

 

[TyeeMan]

A buddy of mine had your same boat, 2016 model year with a 115 Yamaha 4-stroke. The two of us are bigger guys and that boat had no problem whatsoever getting out of the hole and up on plane in any condtition.

I agree with others, either something mechanical is wrong, but mainly you need to know exactly what rpm's the motor is turning otherwise you're running blind.

 

[Sea Rider]

As a first step need to have that tach working and reading wot rpm's right, then going straight for a slip hub test with current installed prop and go from there depending if it's shot or not to troubleshoot other combo parameters. By pure ear sound won't possibly know at which wot rpm the motor is revving at, doesn't matter if having a highly tuned musician's ear for that matter. That's what tachs are for...

Happy Boating​