Hey guys, please help me with a prop question...

I have a 2003 Chaparell 183 I/O that I am going to squeeze one more season out of before I buy an inboard (long story why, but trust me).

I am throwing a Monster Tower on it, and want to do one more thing…..

I have the 4.7l I/O with the stock 3 blade prop. It will push the boat about 55mph, but is too slow out of the hole to properly pull up 250lb skiers.

I was thinking of changing props to get more hole shot (45mph limit on the lake, so I don’t need the top end). I was told to simply go down on the pitch, but that I could easily over rev the engine if I was not careful and blow it. That is not acceptable, lots of different people drive my boat. Others have said that there is a rev limiter. Others, a 4 blade prop.

Does anyone have any experience with this? Can I safely get more holeshot out of my boat?

Ok, for those that say get an inboard right away, here is the deal. Long story, don’t bother reading.

I just moved onto a 800acre lake. The restrictions are:
1. No boat over 20’6”
2. No I/0 over 4.7L
3. No outboard over 115
4. Because the lake has a big ski team, they DO allow tournament ski boats (only some). They have to be a true inboard and approved as an official slalom ski boat. Weight cannot be over 3,000lbs, cannot exceed 20’6”, and NO WEIGHT BALAST ALLOWED ANYWHERE.

The upside is that its only 15 minutes from St. Louis, and I now live there. Lift goes in next week. Yeee hawww. We really don’t know what type of watersports we will get into (wakeboarding, slalom, airchair, etc), so I thought buying a 40k boat this spring would be a little foolish.

Plus, and most importantly, we are lobbying to get V-drives allowed. If they do, then clearly I would get one of those. My boat will be a family boat a lot, just cruising with friends and having a beer.

I am hoping its worth the wait. Either way, I don’t think I can go wrong by getting another year out of my runabout, and driving twenty other inboards this year to get a feel for what I really want. Hope I am making the right decision. The dealer up the street has a 04 X7 with every option (color I want too), 150 hours as a demo boat, and wants 40K. Is that a good deal?

Thanks everyone.

Don't know where you live, I'll assume around sea level.

You prop is probably a 21". I'd go to a 19" SS progressive pitch prop. Better hole shot and only a little loss of top end. Around $300.00

At a mile high, I run a 17" and 19". Depending on the type of day we're having - like foiling or boarding/skiing.

We too used to have a Bayliner with a 3 blade, 21 pitch prop. We simply changed the prop down to a 17 pitch and a 4 blade and had no issues with hole shot. The only thing we experienced was a little bow bouncing while towing a heavy boarder. We actually ordered a certain type of prop that was a resin (plastic) prop, it had 4 adjustable fins that you could change on the fly with an alan key. I can't remember the manufacturers name. Plus you could purchase extra fins to carry on the boat if you ever scraped bottom. The fins made sense to us because we were in a shallow river and buying a rebuilt prop every time got a bit expensive. As far as the tower goes, good buy, even our I/O with a tower was better than not having one, we still progressed. And last but not least, while decreasing the pitch in your prop is to me the only way to solve your hole shot problem, you and all of your drivers will have to pay greater attention to over revving the engine.......stick a small piece of red tape on the tach and tell your drivers never to pass that point.....ever.

Hope that helps a little bit.

We now own a Moomba

When I was running a I/O....switched to a 4 blade stainless and dropped pitch. It was night and day.

For 40K I think there are a lot of other options in the inboard market. Quick search in Boattrader found NUMEROUS '02ish X-Stars(X-2) and SAN's below that price. I am sure there are also a ton of VLX's.....SSV's and whatnot in the sub 40K range pre '05.

E.J.

Robert,

You should be able to change the prop without exceeding the engine's rpm requirements. Most stock props are biased toward a higher pitch I would guess you have a 20+ pitch. You could easily step down to a 17 or 18 and greatly improve the boat's performance.

If I had to abide by your lake's rules I would look for a very clean mid 1980's Ski Nautique 2001 and put a lead filled back seat in it. The other option would be the Malibu Response LXi with THE WEDGE (seems that's what they designed the restrictions around).

The Malibu would be a much better boat then the I/O.

by the way, I did exactly as you getting one more season out of my 95 Nautique by adding a Monster, tower speakers, etc. I feel that the Monster actually increased the boat's value by more then it's cost. Don't forget the racks and mirror, I am even keeping those Monster items for my brand new Nautique!

Another option is to get a torque shift prop from Land-and-Sea. It has about an 11-13" pitch out of the hole, but as the centrifugal forces on the blades increase, the blades shift their pitch. They shift out to a predetermined value that you set. It will not over-rev your engine. Out of the hole it jumps your rpm to the limit and the rpm come down as the boat speeds up. Works kind of like transmission in your car. It is the best of both worlds. You get one hell of an out of the hole shot and you don't sacrifice top end. You may gain some more speed. Because it drops your rpm and increase speed at the same time, the prop increases fuel economy. It worked wonders on my boat. I have modifed 350, so I have I little more horsepower than you, but I am the only person that has skied behind it that can take a full throttle start. Your skiers shouldn't have any difficulties getting up from a lack of power.

These props are a bit pricy, but you can find them used on ebay for less.

Hope this helps,
Aron

I used to have a 19 ft i/o with 4.3L merc and alpha one drive.

a 3 blade alum. 23p pushed ~60 mph, a 21p ~55 mph

a four blade 20p, pirhana (plastic type) was much better for hole-shot. Top speed ~50. I think running ballast eventually weakend the prop, blades seem to break without apparently hitting anything..

I went to 5 blade stainless steel 19 pitch (~300 bucks). Top speed dropped to 45 mph (near over-rev). Good hole shot, but not much better than the four blade composite.

My next choice would have been an alum. four blade, 20 pitch. Cheap and good all-around.

Thanks everyone.

I am down to a just a few things. Please give just a little more info.

I have a 21p now, about 14". I am thinking that a 19p 14 1/2" would be just about right.

My question is....3 blade or 4?????

Also, because I plan on getting a inboard next year, why get stainless???? I wont hit bottom on my lake.

Stainless would give a little better top end compared to a similiar size/pitch alum and is more durable. Not really worth it. Almost triple the cost of alum.

Most people say a 4-blade is smoother than a three blade.

Mercury makes a nice 4 blade, the alpha 4.
http://www.gkpropeller.com/Props/
http://mercruiserparts.stemtostern.com/Mercruiser/mercruiser_propellors.asp

deffinetly go 4 blade ss or aluminum, aluminum is a great value and safer for the lower unit if contact occurs, oh yea tell the others if they cant keep the tach where it belongs they dont drive

i would go to a high-five stainless steel prop. i had 20ft i/o with 4.3 and i ran same pitch high-five as aluminum prop and it would pull my 240lb buddy up on double boot slalom ski. it was unreal the difference. all my buddies that run 4.3 i/o are running high-fives. i am not sure if you have mercury outdrive but if so probably a 21 pitch high five would be the answer