Boat speed advice

[onefishtwofish]

I have a Ranger Cayman 184 (same as 191, just a wee bit shorter) with a Mercury 200 Classic (2004). It has a SS 3 blade prop (I don't have the pitch, I am at work). After doing some reading, I am seeing where folks are getting high 50s and low 60s out of these boats. Mine is about 41-42 with trim down and jack plate up, WOT. It just seems like there is not quite enough power for the engine size/boat size. I have to keep my trim tabs at 90% to keep from porpoising at the higher speeds as well. I don't have a true low water pickup, it is the older style bob's with the 2 hole intake lower and the normal upper foot still drawing water.

I am going to talk with my mechanic about it (he has built custom speed engines and tweaked boats in So Fl for years).

I just wanted to get some ideas if this sounds too slow to ya'll boaters. I have not yet weighed the boat, but I intend to. I really don't need to go any faster than that, I just want to tweak the power of the motor to have that bit of extra oomph if I need it. Where would ya'll start if he starts getting ideas about add ons, fixes, etc. Just lookin for some thoughts in general, I have been a mud motor man for years and outboards are like women to me, full of mystery, purty to look at, but I don't really unnerstand them. I don't want to pour a ton of money into it if I can help it.

[Nathan]

Definitely slow. An 18-19' flats boat with a 200 should be doing minimum 55-60. My heavy 20' bayboat will run ~50 with a 175 Johnson. I run a Silverking Grande Master, which is a heavy 19' flats boat with a 175 V-Max, pretty regularly. Without jackplate it will run ~57. I've heard of people running the same boat to ~63 with a jackplate.
I'll help you with outboards, you help me with mud motors.

Nathan

[Coastal Angler Mag]

That does sound a little slow, I have a 19’ Action Craft with a 200 Yamaha and with a modified prop it would run 63-65 depending on the day. I now have a SS prop I believe it’s an 18 or 19 pitch and runs in the mid to upper 50’s. I’d say take a look at your prop or your motor just isn’t running right. What’s your WOT RPM?

[Gulf Coast]

YOU GUYS ARE NUTS. 40-45 IS TOO FAST FOR ME.

[FUTCHCAIRO]

IF YOU ARE RUNNIN 45 MPH AND NEED TO STOP, DOES THAT BOAT HAVE A SET OF BRAKES ON IT, IF NOT YA NEED TO GET SOME. MY LITTLE STARCRAFT WITH A 85 EVINRUDE WILL RUN ABOUT 45, BUT I NEVER RUN IT THAT MANY RPM'S, AT 2/3 THROTTLE SHE WILL RUN ABOUT 30-32 AND AT THAT SPEED SHE WILL TURN ON A DIME, IF YOU AARE RUNNIN 50-60 THERE IS NO WAY YOU WILL BE ABLE TO MISS AN OBJECT IN THE WATER IF YOU DO NOT SEE IT TILL IT IS ABOUT 100 FT. AWAY. THERE IS NO REASON A PERSON SHOULD BE BLASTING AWAY AT 60 MPH ON THE WATER UNLESS SOMEONE IS DYING ON BOARD AND YOU ARE TRYING TO GET FIRST AID.
PA THE OLD MAN OF THE SEA SEMPER FI

[Gulf Coast]

kinda of my thoughts futch, dont burn much fuel either

[Chalk]

What are you RPMs at WOT?
What is the pitch of your prop?

Look in your OEM manual and look at the recommended RPMs at WOT.

If you are going 4800 RPMs at WOT and your pitch is 19 - you will need to drop down to a 17 to gain 200 RPMs.

If you decide you want to goto a four blade you will probably have to goto a 15

That is an example, but you need to know the WOT RPMs to see if your in the ball park or not.

Trim tabs take speed off quickly...try trimming the motor in and jacking up to make up for the porpoising with tabs up. You can also jack up to gain RPMs but need to watch the water pressure.

My HPX tunnel with a 70 hp will hit 38 with two anglers

[What a mess]

Trim down is putting on the breaks plain and simple, if the boat will not run without them down there are several solutions.

[BAD BEHAVIOR]

Very similar to the problem I have on my MAVERICK. Too much weigh on the transom. I exagerated the problem by adding the jack plate. I made it even worse by adding a four blad eprop. Still trying to find an answer myself.

[Chalk]

If your porpoising your trimming too much in most cases....my ghost was only good for two slight bumps up...if you jack up you have to trim in. Ranger Banshee I had was no trim period or it would porpoise. Jacked up trimmed all the way in and it would bounce just a hair. HPX is only good for a few bumps or it will start to hop.

Best to run on a calm day and play around with the trim to see how much or how little it takes...its hard to figure it out when its choppy

[Jumptrout51]

Very similar to the problem I have on my MAVERICK. Too much weigh on the transom.

DUH!! Move forward BB.

[onefishtwofish]

Great thoughts guys.

I am porpoising with trim all the way in. Can't run without trim tabs down at higher speeds. So maybe I need to check to see if the motor is trimmed in as far as possible, right? ie is there a setting that is keeping it from trimming all the way in.

Jack plate was as high as I could put it the other day and still keep water pressure up. Durn nose cone should let me go a wee bit higher, but it is a dumb design (why have a low water pickup AND open ports above it? makes no sense).

I am pretty sure WOT was 5200, but I will have a look again on a calm day (ain't gonna be Wed in Aucilla, dats fo sho!). Range from 5000-5600 depending on where I look, so I am in the ballpark there. It is definitely pretty arse heavy, especially with bait and livewell full and 3 big uns sitting on the bench seat.

Futch, good points and I don't wanna run it that fast, really ever, I just want to make sure that it is running as efficiently as possible (the less rpm I use to run my comfortable cruising speed, the more $$ I save).

One more question, more blades means better hole shot and lower top end speed (in general with same pitch). Is this correct?

[Jumptrout51]

One more question, more blades means better hole shot and lower top end speed (in general with same pitch). Is this correct?

Yep.

[Chalk]

Same pitch in four blade will be less rpms...you have to drop down in pitch when you add a blade.

5200 is low IMO for the motor...I would be shooting for 5400 to 5600....I run mine at 5600

Your not going to see optimal speeds with a baitwell and livewell full of water and three adults on boards.

If you are porpoising trimmed all the way down...you may need transom wedges

[What a mess]

Give him a wedgie!