Bow-lifting prop?

[traveler]

I've got a fiberglass 20 ft. Champion center console, 150 V-Max. Been running it 2 years now.

I bought it used, and it's always seemed to run too "flat"...can't get the bow to trim up, and it tended to blow out in turns, even trimmed down. I'd been meaning to get someone who knows about these things to take a look, and finally got around to it. My mechanic came out for a test run, and agrees 100%...it's plowing thru the water...so we're looking at the prop first.

The prop on it is a 3 blade, 21 pitch yamaha aluminum. We tried a stainless 4 blade 17 pitch and it was NO better...well, it did hold in the turns better, and it brought the rpms up a bit (from 5200 to 5400), but the V-max should run close to 6000.

The prop dealer doesn't have another prop that will fit for us to test, so I'm a little stuck at the moment.

Thoughts?

[Esox_Magnum]

Maybe drop it a hole or two to get it in the water more??? Do you run a jackplate?

[traveler]

theres only 1 hole to go...doesn't seem like much, but then again, i don't know much:) . The mechanic mentioned a jackplate as a possibility, but we're starting with simple first...

[Esox_Magnum]

Not real familiar with that boat but on 2nd thought it could be under powered. Just a guess but max HP rating of 225-250???

[JohnMickish]

See if you can borrow a Rev 4 four blade stainless prop from a propshop or a dealer. The Rev 4 is designed for bow lift on fiberglass boats. This is one of the prefered props for Ranger 620s, regardless of what engine is on the back. If you can't find one of these just try ANY stainless prop that has the right pitch. You have got to get rid of that aluminum prop.

Aluminum works great for beer cans, not so much for propellers after you get above about 75HP. There used to be a guy on here called Jay Solderbloom who knew alot about props. I don't know if he is still around but if he is, that's the guy to ask.

[traveler]

Esox; boat is rated for 175hp, so my 150 is 85+%...should be enough power easily.

MNfish; I expect stainless will help, but the one we tried so far did not. I'm close enough to Jays shop that I'll try him next and see if he has a prop he recommends.

[RonT]

Give Jay a call and I"m sure he can help you out. He helped me out a couple of years ago with a stainless prop that has been a perfect fit for my boat and motor.

[BoxMN]

Try a 19" Tempest Plus...

[JohnMickish]

I think the problem you had with your first stainless prop was that it was pitched wrong. Going from a 21 to a 17 is a huge jump. I also don't know how you only got a 200 rpm increase in that??

If it where my boat, I'd be looking to try a Rev 4 with a 21" pitch, possibly a 19". Make sure you experiment with pulling some or all of the plugs out of the prop when you test as well to make sure your holeshot stays good.

[traveler]

I have a call into Jay S. now ...we tried the 17 cause thats what the local shop had for us to try, I expect we'll be trying a 19 if Jay has one. Hopefully a Rev4 or similar...

[PerchJerker]

Pitch is going to help your boat run at the proper rpms, but it's not going to do anything for bow lift (unless your boat runs REALLY bad with the prop on it now). Blade design on the prop will do more for bow lift.

It's surprising to me that a 17 pitch prop is running that low of rpm for you. Dropping pitch should increase rpm, increasing pitch will drop the rpms. I would have thought you'd be over-revving (or at least close to it) with a 17 pitch prop????

Can your motor be raised up on the transom? Many boats have the motors mounted lower than they need to be. Raising the motor will get you another 100-200 rpms, and will get more hull out of the water. The key to watch for is to make sure you're getting enough water pressure to cool the motor if you raise it on the transom.

One other thing -- hows the weight distribution in the boat? Bow mount trolling motors, anchors, coolers and deep cycle batteries can put a lot of weight in the bow. If you can relocate some gear, or even take it out of the boat for a test run, that might help you get the bow up and then you can go from there.

One last thing -- have you called the boat manufacturer to get a recommendation from them? They should know what props are likely to run best on their boats.

Good luck getting it all sorted out.

[traveler]

Perch...we did gain some RPM's going down from 21 to 17, but not as much as we expected either. Maybe going from 3 to 4 blade had some effect there?

We have only 1 hole either way on the transom...my mechanic doesn't think that 1 hole either way is the culprit here.

I did get hold of Jay Solderblom and I'm picking up a prop from him...3 blade stainless, preformence prop with a lot of rake. He says it WILL raise the bow, then we'll see where the RPM's are.

We thought about the weight, but it's not an issue here. Batteries are amidship...really no weight to speak of up front.

Boat Mfg. is a problem. Champion built a very popular 212 for years, but for a couple years they had a different company build this particular 20 ft'er. backcountry is still in business, mostly flats boats (and well reviewd) but I've had no luck finding much out about this boat from either mfg.

I'm looking on a couple boat sites for owners of this specific boat to see how they have it set up...no luck yet.

Thanks for all the ideas guys...

[JohnMickish]

Let us know how the prop works out.

[traveler]

will do. It'll be a couple days...jay had to order a hub for it. Hopefully get it in the water friday or sat. Stay tuned...

[Whoaru99]

Might be wise to check your tach against a known good one if you haven't, especially considering you don't seem to get expected reactions from pitch change.

Mercury indictates RPM should change by roughly 200 RPM for every 1" of pitch. Going to a 4 blade prop of same pitch usually doesn't change RPM too much because the 4 blade is generally smaller diameter.

[basser]

I am surpised at the low pitch you are using. I have a 150 VMAX - granted it is on a 18.5ft Skeeter- and I am turning a 25M at 5500RPM - I would think that you should be using a 23M minimum on that motor, should get the R's up and provide plenty of lift. Just my opinion though as I dont know how that Champion hull is designed. It also sounds like your motor is too high on the transom if you keep blowing out. I am also wondering if you are getting the throttle all the way open. Do you have a hot foot on your boat? Check to make sure the throttle is opening all the way first - that 17 pitch prop should be putting you at the limiter quickly on the VMAX. Hope some of this helps you out.