Home Forums Fishing Freshwater Trim Tabs/Smart Tabs?

I have a brand new Smokercracft 161 XL equipped with a 60HP Mercury 4 Stroke.

With three adults in this boat it will not plane out, it actually points at the sky. The max rating for this boat is 75HP.

My dealer and Smokercraft both claim their is nothing wrong and they both suggest I install a set of trim tabs or Smart tabs.

My question, with these tabs installed can you still install a small trolling/kicker motor?
I am a walleye fisherman and backtroller. I would like to add a 6hp kicker to this boat, but not sure if I can with these plates hanging off the back?

My POS boat.
http://www.smokercraft.com/showroom/fishing-boats/pro-angler/161-xl

There is a lot involved in this topic. I'm far from the guy to know the answer, but having had a few boats I can tell you that the depth adjustment of the motor on your transom may be the easiest fix, or the type of prop.

Keep the motor lowered until near full speed then start lifting it a little bit at a time until the boat levels out. Once you hear the prop cavitate click it down once. I assume you have an electric motor tilt button on a motor that big.

Trim tabs will likely be in the way of the trolling motor. Unless it's electric or you have an extension mount.

The prop pitch and motor depth is critical to proper overall function. I went thru this myself a couple boats ago.

An alternative to trim tabs is a motor mounted Doel fin or hdydrafoil. I had a Stingray fin on my 18' Klamath and it definitely got out of the hole flatter, on step quicker, and improved the handling in rough water. I tested the boat with it installed and then removed and went back on and stayed there for good.

A Dole fin will help but it's not going to make up for a lack of thrust if the engine is bogging down. If your boat won't get on step will only three people on board then something is wrong and the prop is a very likely suspect.

Did the dealer or Smokercraft mention the prop or suggest trying a different one?

What rpm does the engine run at when it is on step?

Does it run at the max rpm the motor is rated for?

If it doesn't achieve max rpm you'll lose both top end speed and power.

I tried four different props on my boat/motor. A 13" pitch, 15", 17", and finally settled on a custom 14" pitch that I cupped. It was the perfect prop for both speed and carrying a heavy load. FWIW, I had 40hp Evinrude 2 stroke on it.

And like JJ mentioned ... "The prop pitch and motor depth is critical to proper overall function."

Here's some really good info on boat propellers.

http://www.mercurymarine.com/propellers/

One thing I'd suggest is see if your dealer will loan you a prop, to try out, that's one step lower in pitch.

By "Motor Depth" do you mean having the trim all the way down or do you mean the position the motor is bolted to the transom?

Smokercraft, Mercury and my POS Dealer all say this is the correct prop. It is a 10.38 x 12.

I have visited a few Prop calculator sites and their recommendations are all over the place.

This one seems to be the most informative and thorough, but I duno.

http://turningpointpropellers.com/

These guys say I should run a 12 x 8-9-10.5.

The RMP of this motor is 6000. With three people it points at the sky and will not get over 4000.

I am running this boat with the motor trimmed all the way down and the trim stops on the motor are at their lowest point.

Thanks for the help.

Mounting height is what I was referring to and the dealer should have it set correctly but ... ?

Just to clear things up. Does the motor reach 6000 rpm at full throttle, on step, with a light load or is that the specified max or both?

I gotta add this. When you start looking at different brands of props, different styles, 3 or 4 blade, and different diameters it's tough to compare apples to apples. That's probably why the numbers are all over the place.

Performance changes when you compare props with a given pitch but a different diameter ... and a different style, blades, etc.

The boat set up with you and gear will require a different set up then three guys and gear

It's a compromise with a light boat to make it proper for every situation. My current boat is perfect with my wife and son.

But two other guys in the boat and it will lean to the heavy side. I could adjust it to work with this load but then it would be off with a lighter load.

It's never perfect unless you add adjustable trim tabs. Which are a hella expense on a boat that size.

How many RPM`s can you turn with a full load? With a four stroke you need to be able to turn between 5500 and 6000rpm`s at wide open throttle or you will have a problem planing.Anything under 5500 requires a lower pitch prop.Rule of thumb is 300rpm per inch of pitch but it really depends on hull style and load.

Full load is only what I have done so far.

That is myself 185lbs, My buddy 210lbs and his girlfriend 160lbs, with a full tank of gas 20 Gal.

With this load it points at the sky and will barely get 4 grand.

My buddy (210lbs) hand to sit on the bow mount trolling motor to get the nose down, his girl friend had to sit on the floor beside him.

Whatever pitch prop you have you need to go down at least four inches of pitch possibly six inches.More if going to a four blade from a three blade. You have to get those rpm`s up or it will never plane correctly.Also check the height of your motor setting.Your anti-cavitation plate should be level to no more than two inches above the bottom of your hull.When trimmed all the way down.

will do thanks.

JJ,

I respectfully disagree ... at least in part.

Yes, there are compromises to made but a 16' aluminum boat with a 60 hp motor should be able to carry three people and get on step with no problem.

I don't believe trim tabs are the only solution either. The right prop and a hydrafoil should correct the problem of getting on step with a heavy load. I'm going out on limb by saying that since I've never even seen a Smokercracft 161 XL but based on my experiences it should work.

Whether or not a prop change is needed depends on what rpm it's running at WOT on plane. That's also an indicator if the motor is making 60 hp. Another factor in deciding if a prop change is necessary is how fast it gets on step with a light load.

Down four to six inches of pitch or more?

No way. How can you guess without knowing what rpm it's running at WOT on plane?

And ... The OP hasn't even tried to get it on step with light load.

How many times have you had this boat in the water?

You've never tested it with just yourself in the boat?

Has it ever been on plane?

Here's my last bit of advice ...

Take the boat to lake and see if it will get on step with just you in the boat. If doesn't ...

Take it back to the dealer and tell him to fix the motor and forget about props and trim tabs.

Good luck.

Not trying to step on anybodies toes but this is what I do for a living I have propped more than twenty thousand boats in the years I have been doing this.There may very well be something wrong with the motor.But until the Op can get the rpms up where they belong the boat will never perform correctly.Now that may mean two different props for different tasks.Sometimes it works out that way.I always recommend taking the boat out with your normal load and propping it for that load.On some boats a hydrofoil can be detrimental to the handling or even dangerous in a few cases.And it is always hard on the anti cavitation plates.I weld dozens up each year from the extra strain.

Well ...

I'm no expert on boat props but reducing the pitch by 4 to 6 inches doesn't sound right to me. I have difficulty believing that a factory prop, if it is correct, is that far off and especially since it's on a 16' aluminium boat. The standard prop may not be perfect but it should at least be in the ballpark.

mch has given you good advise. I have ran many bass & fishing boats & the set-up is incorrect. This is something the dealer should correct. Probably a 3-4 blade SS prop will solve your problem after dealer makes adjustments. Even with an aluminum prop you should be able to plane with 3 anglers. I have a 14' Smoker Craft that I use to fish ponds & small rivers & while its a far cheaper boat than my Ranger is quite serviceable. I have added a Whales Tail to the last several bass boats I ran, but for a different reason. If the lake is really wind blown this helps me keep the bow high to ride over the swells. Also helps a bit on the hole shot.

You have received excellent advice. Sounds like you need to reprop.

I would like to talk about the trim tabs. I installed Bennett trim tabs on my Deep V center console 1910 trophy bayliner 25 years ago. Only thing that wore out was the joystick control which I replaced this year.

I feel the trim tabs were a major improvement in a boat's performance. They will get you on plane very easily even without getting hard on the throttle. I frequently will ease the throttle open saving gas and the work the engine would otherwise do.

You can stay on plane a much slower speeds which reduces the beating you sometimes get when knifing into big waves. It also brings the bow down so you cut through a wave instead of getting hammered.

When I was at Lake Powell I cruised looking for boiling stripers. After catching a few I would never adjust the trim on the motor, bury the trim tabs and get up on plane to the same RPM and cruise again.

If the boat lists while on plane due to angling into waves the attitude can be leveled out or even increased so the gunwale on that side is higher to prevent waves from splashing occupants.
I would never own a boat without them.

I would call Bennett Marine to see if your boat has enough room to put them to use.