Prop Selection

[BassKnuckles]

I see the big 'C' has a prop that is 14 1/4 x 25 and the prop I currently have on my boat is a 14 1/2 x 25M

Would there be a issue if I installed the one from the big 'C'?

I'm not sure if that's what I want though either because it says it works with your hub kit. Well I need my hub replaced on my current prop so I'm not sure how it actually works.

[BassKnuckles]

Will a OMC prop 25 V6 fit my Yamaha 200 HP that currently has a 25 on it.

[hydro]

Why are you replacing the current prop? Is it damaged?

25" is quite a bit of pitch and if your are in the zone where your boat can actually use that much prop, it's worth getting some advice from someone who actually knows how to spec a performance prop. The wheel you can get at the big "C" is not a performance prop.

What kind of boat are you running and what is your current speed and WOT RPM?

[BassKnuckles]

My current prop might have a bad hub. I always needed to get a back up so I thought I'd start looking and pick up something on C L and then have my current one repaired.

I have a 1996 19' Skeeter 190 Dual Console with a 200 HP Yamaha 2 Stroke.

The fastest I've ever been able to get it up to was 55 or 60 mph.

[hydro]

I would think that boat/motor combination is capable of more than 60 MPH. Do you know your WOT RPM? Do you have a jack plate or is the motor bolted directly to the transom?

[BassKnuckles]

I do not know what WOT even is. I thought the same thing about the speed.

I'm going to run over to A1 tomorrow and see if they can tell if my hub is spun and if it needs to get replaced. Sucks though because I think it will take over a week if they have to send it out for repair.

I do have a plate. I've never messed with it because I have no idea what I'm doing. It looks like all I have to do is losses the side bolts and then adjust up or down with the top bolt and re tighten everything down.

The main issue was that the rpms would spike. Also she. I was starting out or going to max speed the motor would slow down like it was losing something. Initially I thought it was a gas issue. I replaced the fuel pumps and filter with no resolve. Also added Seafoam.

I just got done replacing the fuel l e and bulb.

I just hope it's the hub!!!

I need to go online a d find a video or something that explains the jack plate.

[hydro]

Sorry about the terminology. "WOT" is Wide Open Throttle and it is important in telling if your motor is turning at the RPM where it makes the maximum horsepower. You want to be running within about 200 RPM of the maximum rating under typical boat loads. The jack plate can raise the motor to free up the prop at higher RPM's and it can make a huge difference in how the boat performs and handles. Jack plate height is referenced by measuring the centerline of the prop shaft in reference to the running surface of the bottom of the boat.

I have a similar boat, a 20' pad bottom "Bass" type hull with a 200 Mercury and I run my jack plate so that the prop shaft is 3 1/4" below the pad (Pad is the center flat part of the hull bottom). When I first got the boat, the prop was set at 4 1/2" down and the boat torque steered, had a tough time getting on plane and only managed about 50 MPH. By raising the motor I picked up over 10 MPH, lost the torque steer, and now it planes out much faster. Be careful though, if you raise the motor too high the water pickups will suck air and you can have cooling issues. Watch your water pressure gauge if you have one. Every boat is different so it takes some experimenting to get the setting right.

Ps. I would bet your boat should run in the mid to upper 60's when set up correctly.

[BassKnuckles]

How do you check what your prop RPMs are under a full load? I can bring home a tachometer from work since I perform calibrations I have some access to some decent standards.

Are you sound this while your on the lake? I was wondering about adjusting the jack plate also if people adjust them on the lake or at home.

[boatfixer]

Do you already have a tachometer in the dash?

That engine should have a 1.87:1 gear ratio. For every 1.87 revolutions of the powerhead, the propshaft will rotate 1

[hydro]

If you need some help I would be willing to go for a ride with you. I am in the Buffalo area.

[JohnMickish]

If you can still get up to speed, the prop is not spun. That is a pretty aggressive prop for a small motor like that. I run a 23 pitch on my 250HP+ glass walleye boat.

RPMs at wide open throttle is THE tuning tool for props. Without knowing it's all just a guess.

If you want to adjust the jack plate, adjust it so the cavitation plate is just out of the water at speed. That will take a second guy in the boat to look for you.

[BassKnuckles]

Thanks for all the help!

I live in Montrose so if you are willing to and I get stumped that would be great.

I dropped my prop off at A1 this morning, they said it might be back by Thursday but I will see if guess. One guy there said it didn't look spun and another guy thought it did. I personally could not tell.

That prop was the one that came with the boat when I bought it but I am the 3rd owner so I'm not sure what it initially came with.

I am glad it's windy today though. I'm not getting bummed out not being out in the water

[hydro]

BN, Maybe next weekend on Buffalo after you get your prop back. That's close to both of us and the north access has space where we can work on the jack plate settings. PM me with contact info if you are interested.

[BassKnuckles]

Well I just heard back from A1 and they said the hub is fine. Which really sucks because I'm not sure what to do next.

How is a place going to figure out what the problem is? I have a feeling this is going to turn out to be expensive.

Any thoughts what my next move should be? I wish it was fishing, I really need to get on the lake.

[bASS_BLASTER]

First. Park your boat, use a level stick and level your pad. Then level your motor vertically using the stick. Measure bottom of floor to your pad. Then measure the center of your hub prop. Both center hub and pad should be exactly the same length from ground up. Once you established that for your boat and setup, your center should be 1.75" - 2" below pad. Lower your jackplate and mark your gauge. I would start with this, run your boat and watch your water pressure. Do not let it go befow 15psi. Do this to see if you can get better speed before buying a performance prop.

Should you want a Performance prop, many skeeter guys are using Yamaha T1 25P - 27P and Tempest 25p-27p and few Hydromotives. If you want every little bit of top end get a lab finished. The bigger the pitch, the faster top end you'll get but your holeshot will suffer. I think for your boat & setup, a 25P is perfect for all around.

[SkunkedAgain]

Any thoughts what my next move should be? I wish it was fishing, I really need to get on the lake.

Yes, listen to Hydro

[hydro]

You said you replaced the fuel filter. Was it the one on the motor? Did you check to see if there was another filter somewhere under the splash well between the fuel tank and the motor? Look for a canister type filter that would also be the water separator.

[BassKnuckles]

Yes it was just the one on the motor. Tomorrow or Friday I'm going to continue going through everything and will look for what you are talking about.

So far I have

1. Replaced fuel filter on motor

2. Replaced 2 fuel pumps

3. Had the hub verified that it was not spun

4. Replaced the fuel line and bulb (have not taken the boat out yet after this)

I am going to measure the jack plate as you mentioned also.

[BoxMN]

Even after you verify that the motor is running properly, if he will, take hydro for a ride. He will help you out more than you can imagine! He knows his stuff. Good luck.

[BassKnuckles]

I'm at work right now but I am just thinking about how my motor might have been raised up.

What could cause my motor to become higher out of the water in time?

Like I said I'm at work and still have to do my measurements but I cant stop thinking of possible problems.

[marine_man]

Before we get into prop tuning... it sounds like there is a mechanical problem that needs to be resolved.

Can you provide some more detail on what the specific problem is? What you've shared so far is:

The main issue was that the rpms would spike. Also she. I was starting out or going to max speed the motor would slow down like it was losing something. Initially I thought it was a gas issue. I replaced the fuel pumps and filter with no resolve. Also added Seafoam.

Did you have an indication it was a fuel pump or filter problem? Does this problem only occur at full speed, or at mid throttle as well, etc?

marine_man

[hydro]

Marine_man is right on the mechanical issue. That definitely needs to be resolved before doing any "tuning" of the ride and performance. If you do not feel up to diagnosing and fixing this yourself, I recommend Dingmann Marine in Annandale. John knows his stuff and will help you out. Get it running right and then we can take a ride.

[BassKnuckles]

So I was just reading about the cavitation plate where should this be at when my motor is trimmed down? I took some pictures.

Boat Rear

Boat Rear 2

[hydro]

With a boat like yours, the cavitation plate really has nothing to do with the performance except when first taking off (hole shot) when it acts as a lever. As you can see in pic 2 it is way above the running surface (where the drain plug is) and out of the water when at speed. The running surface (pad) is what you need to tune the height in relation to. Tuning motor height is a dynamic thing and can only really be done by trial and error on the water.

Did you get the motor issue resolved yet? Once that is done, then look at setting up the motor height.

[BassKnuckles]

No not yet but if the cavitation plate is coming out above the water wouldn't that induce air and cause my boat to surge like it does?