Boat tried to sink

[phragle]

Disaster averted . Now to pull the motor and replace steering pin seal

[Ratickle]

We need more info!!!!!

[phragle]

Boat was tied up in the canal around the corner from the tiki bar.... neighbor came over saying "your bilge pump is running like crazy"

[fund razor]

The edgewater canal?

Not sure I know the tiki bar in question.

Putting in at Cullen a little later if you want to go for a ride.

[phragle]

Friends house/tiki bar on Sandusky Bay

[MOBILEMERCMAN]

Hardin sells a SS swivel shaft. Good chance you'll find the existing one is rusted, grooved or pitted.

http://www.hardin-marine.com/c-733-accessories.aspx

[MOBILEMERCMAN]

While the engine and transom assembly is off the boat you might as well raise the entire thing a a few inches.

[phragle]

While the engine and transom assembly is off the boat you might as well raise the entire thing a a few inches.

NOOOOO!!!! I finally have this thing handling really good. Chine walk gone, low and mid speed torque lean gone, and this is with the tabs all the way up. What the boat needs now is more horsepower.

[phragle]

I have to admit I spent some time on a 25' laveycraft this past weekend, and was getting a little envious how it ran around the bay so well, had more room than my boat and was considerably faster than my boat with the same power. Great boat, lots of room, great layout nice little cabin, excellent fit and finish, really a nice boat. soI rode with him when we went out to Kelly's As soon as we left the protected bay waters and hit the washing machine, I was consumed by the fact that I love my little boat...That in this slop he was choosing lines thru the chop, working the throttle and really trying not to jam our spines thru our heads.... In my little boat, in that chop, the throttle would have been bungy corded to the dash with one hand on the wheel while I played with the stereo and drank my pepsi with the other wishing for a little bigger water.

Dont get me wrong, the Lavey is an excellent boat for running west coast Colorado river, havasu etc.. But I boat on Erie.

[MOBILEMERCMAN]

What the boat needs now is more horsepower.

Its not just how much power you have but, how much drag you don't have that increases performance.

Thought since you completed glass daves glass class that it would be a less expensive way to go faster. Sure you have to continue to work on set up. Adding power is a process too. Expensive parts and labor, upgrading drive pieces ect.

I went from 72 to 80. Same engines same props. Mine too were in the basement.

[fund razor]

I boat on Erie.

Crazy bastard.

[Ratickle]

While the engine and transom assembly is off the boat you might as well raise the entire thing a a few inches.

What about a shorty lower instead?

[MOBILEMERCMAN]

I cant tell from here. The pic of the transom in his other thread seems to show it low. Standard height is with cav plate one 1" above bottom for a single. The images of it running shows it may be a bit higher than that. Again cant tell from here. The shorty will only provide a benefit if the fat part of the case where the cav plate exists is clear of of water hitting it. Like when it is mounted higher then standard. The shorty will raise the shaft but if assembly is too low it still drags the fat part thru the water. Need to parallel the drive with bottom and provide a pic from same line of sight to give an opinion.

It may be good where it is. It depending on his target speed. And since he runs in lake crazy a little low is good. I made that comment about raising it in part in jest. Since he talked about pulling it all apart again. An easy test would be if he tried your shorty.

[fund razor]

And since he runs in lake crazy a little low is good

Mine seem pretty low and I find this to be very true running in our crazy choppy sloppy lake.
Not to hijack, but quick question: what is standard cav plate height vs. bottom for twins?

[MOBILEMERCMAN]

When I say standard I am referring to mercurys installation manual where standard is where the cav plate is even with bottom when trimmed parallel. Most sport boats built since '87 { when the mirage propeller was introduced } have them mounted a couple inches higher. When mine was built in '85 the propeller selection was limited. Mercury had the Cleaver and Kiekaffer offered their sport cleaver over hub style. Standard is in effect a cabin cruiser set up. It will work well up to about 60 or 70mph. Once the mirage came out the drives went up. Over time they continue to go up with advances in propeller and hull designs.
Speed masters are surface drives and are different they refer to prop shaft height relative to bottom in the installation charts.

From what I have experienced prop shafts that are in the 4 inch range from the bottom work well for for speeds in the 80 plus mph range. On a bravo the prop shaft is 9'' below cav plate.
This is in general other factors apply. Every boat is different. Different cg's, different notch dimensions, different deadrise, ect .
Singles add the inch in part because the water rises from both sides converging in the center.

Another thing to consider that I see often gets over looked when raising to the limit on twins and triples is the prop height relative to the pad or bottom of V. The last thing you want IMO is to have a situation where the hull is touching the water while the props are clearly still in the air. Boats with 26 degree dead rise and side by side engines and many triples are especially subject to that situation.

Boats that are most fun to operate can skip across the tops without the props spinning completely free.

Last thing to mention is as the boats leave the water there is a moment where the props are still biting and the hull is clear. At that moment you get 100 thrust { provided your still on the throttle } with zero drag. That moment exists as it re enters too. It will lung forward every time it leaves and re enters. Props that are too high relative to the bottom of the running surface will not. Those same boats generally wont carry well and will tend to wet the entire bottom as they re enter. That is why I say a little low in rough water is better then too high every time.

Got carried away.

[fund razor]

Thanks Jim. I went from a practical to theoretical understanding in one post. Thank God I have nose cones as low as my B1s hang.
But it completely explains why it handles like on a rail unless I trim to the moon. Extremely forgiving boat to drive.

I'd be a shorty candidate if I was trying to max it out I guess.

That was an awesome post. Thanks again.

[phragle]

Jim, how am I measuring? Also when figuring marking the drive on the indicator as parallel to the bottom????? I ask because I have that little delta pad that is at a different angle then the rest of the bottom.

[MOBILEMERCMAN]

Is that pad on every Avanti like yours? Do you know if it was molded that way or changed after ? By pix it appears to be about 2 ' long. I suspect its intention is to help more water get to the intakes. I would measure from either side of it. Keep your eye out for a housing with low water intakes. You may find you would want to fill that back in.

When you parallel the drive take a pic with your eye on the same line looking under the boat past the drive and prop. Something like this

[Pete B]

I know someone that is on this board with 4 boats that have more trailer time Including a Blackthunder, you should start your winter project with one of these.

[MOBILEMERCMAN]

Are the names Dusty, Fuel me, Cruise me, and Rusty?