stern heavy
 

got a 71 20 ft cc seacraft, closed in transom and installed a livewell in transom,26 inch stainless marine bracket.I have played with some weight up front and as long as I,m the only one in it its great,but when I have some else with me I have to run really trimmed down.I,m running a laser11 19stainless prop.I use the boat mostly for offshore fishing.I,m wondering if anyone has experience with this setup and if I need to go with trim tabs or smart tabs or just one of those doel fins.Oh yeah its a 97 merc 200 top speed 53 mph gps.Got a great deal on the motor,can,t afford to change motors.Any help would be greatly appreciated.Thanks

Re: stern heavy
 

Does the boat porpoise if you don't trim down?

Re: stern heavy
 

Yes especially if my livewell is full and i,ve got a passenger behind the console with me

Re: stern heavy
 

outboard most likely is hung too high

Re: stern heavy
 

Yep just went out and measured and best i can tell while fighting off a swarm of sqeeters is it looks like cav plate is 5 inches above keel

Re: stern heavy
 

when I put the bracket on my 18ft it did the same, I installed a doelfin and that fixed the problem I would suggest you try that they are inexpensive and do work.
Tony

Re: stern heavy
 

Don't forget to drop the motor down on its mounting bracket, if possible!

Re: stern heavy
 

here is a previous post about engine mounting here is the post

Get a straight edge and bring the motor to neutral trim, see where the cavatation plate lines up should 1 to 1 11/2" above the hull bottom. Props with long blades or alot of cup can go higher

Re: stern heavy
 

i,ll start experimenting with it and post results i have to feather the throttle now to keep engine from gettin swamped on stopping.

Re: stern heavy
 

I think this is my post and thats only for transom mounted engines - the set back from the bracket changes everything. Usually the issue is either motor too low or too much weight in the stern or both. If its not cavatating then its not too high.

Re: stern heavy
 

ok just measured my leading edge of lower unit is 40 inches back from transom and cav plate is 4 inches up.will try to post pictures

Re: stern heavy
 

I'm running a 30" setback bracket and my cav plate is 3.5" above keel. I run a Doelfin and a 4 blade prop for extra stern lift. Low speed planing performance was terrible until I tried a 4 blade prop; will now plane at 12 mph!

Re: stern heavy
 

http://marinedesignsbyvonwidmann.com...43-492x365.jpg

I think something like this would help a bunch. I can plane at low speeds with my bracketed seafari, but it's still light in the bow at speeds even with a Mirage Plus or Rev 4.

Re: stern heavy
 

Take note about ESD's point about the motor height relative to setback. 1 to 1-1/2" is for the transom mount. Armstrong bracket calls for raising the motor 1" for every 12" of setback so at 3.5 - 4" you're probably close now.. might need drop one more hole.

Another issue is your Laser II prop - its probably the wrong prop. You have a prop with a lot of rake that gives you more bow lift than you want.

You might try to borrow a Black Max (3-blade sternlifter) or a if you can, an aluminum four blade like the Alpha from a shop or somebody. I all but guarantee your hole-shot will be cut in half and you'll greatly reduce that bow rise while running. If the Black Max works you can get it from PowerTech or Propco in stainless.

Re: stern heavy
 

thanks guys i raised the motor up one hole and it seemed to ride better in the river,however i took it offshore today and whenever the boat would come off a wave (2 to 3 about 6 seconds apart)it would dive to port abruptly, dangerous!When I got home I started trying to figure out what was going on and i discovered my torque equalizer was missing could that be the problem?

Re: stern heavy
 

If you're referring to the little trim skeg as absent, a 200 Merc 2-stroke definitely creates considerable steering torque especially w/o hydraulic steering. The tab won't solve your porpoising but it may help counter that dive to port quartering a swell...those little tabs have amazing influence, the final say you might say, almost like a second rudder

Re: stern heavy
 

when you say black max prop,i have a 1981 black max 150 with a 3 blade alum prop.is this the prop you are talking about.

Re: stern heavy
 

It may be. The Black Max was a motor name given to some of the Merc V-6s.

The Black Max propeller is an aluminum prop designed for aft heavy apps like stern-drives, good chance that one came with that 150. It is a classic blade that offers unmatched stern lift in a 3 blade. It has very little rake and cupping and is easy to turn.

Quicksilver's equivalent prop is called Black Diamond. My understanding is that the prop used to be available in stainless...

I believe Propco still makes them in stainless and PowerTechs MQF and MQS (MQS for your motor) series are also the same shape with slightly different pitches.

The Black Max is everywhere for around $100 -130. Chances are that your other prop is just that. Swap em out and see but be careful that you don't over rev as the prop on the 150 likely has a lower pitch than the Laser II but if its a 19 pitch and compatible, try it out. And definitely get a trim anode on there. Good luck.

Re: stern heavy
 

Those little tabs are called torque tabs for a reason.

Re: stern heavy
 

I agree that Lazer is probably not a good fit for you