GS and setback

[citabriatom]

What are you GS owners using for setback?I searched every thread I could find and am more confused than ever.Mine currently has 9" but I've seen everything from 3 to 14.I am more interested in hole shot(for skiing)but don't want to give up TOO much top end.What is a good starting point?I've got the motor off and the tank drained to do the transom update,so this is a good time to make a change.Thanks alot,Tom

 

[LAAllison]

Tom., I'm right there with you. 9" and it seems to do very well. I use a 26 Trophy to ski with. It pulls me fine and will still run 85-86. Change to 28 chopper puts me at 90. Boat is a 95 and engine is 97 SM 225. My son runs 12" but he runs 280 power and never has tried to pull a skier or tube.

Art


Roll Tide

 

[citabriatom]

Thanks Art.Have you done the transom update?It has been a load of laughs so far(NOT!)

 

[whipper]

I use 12inch with a tape its more like 11.5 and ski and tube all day long with 3 or 4 in the boat and gear for the day. The previous owner had a 280 on her but Im useing a 225 promax with the same setback. There about the same weight of engine. Its all about were your wieght is. The basics are if your moter is heavier than you use less setback. So the guys with the XS are running with less like 3-9. When were out as a family there is more wieght in the boat. I put the kids in the back and my wife sits up forward. There is usually some stuff in the bow also like a tube and skis. The starboard aft locker usually has the cooler full of ice and food. I also put my anchore there. What Im trying to say is you can offset the engine wieght setback buy distribution of wieght in the cockpit to creat the same fulcrum point as if you were running light with just about any setback I believe. When I have full fuel I think less setback would be nice. I havent tried other set backs I just use what I have and make it work. The 225promax is as light as they come. Because of the way the GS loaded 60-70% of time I would like to try 8 or 10 some day. I think JR uses 12 and Ziemer uses less if im not mistaken like 9.5 or 10? Jr has the same moter as me but Ziemers is a 260 I think. Skydog had a nice GS with a 260 and used 8 both Z and Skydog run over 100! I think at 9 your right in there. You have a 15 mid right? That makes a differance also. Try less and see how see goes? Its a pain in the but to have to fart around but at least youll know. I would like to try less not more my self. Mostly because there always seems to be a lot of extra people on board the majority of the time.my two cents, James

 

[JR]

On the Grandsport, My experience is: 20" mid=less setback, more HP [260-280]=less setback.
With my Pmax, my sweet spot is 12"+the 2.5 inches that is built into my 15" midsection.
JR

 

[hack02]

But you don't count the extra 2 inches for the 15 because the gearcase is in the same position as a 20. The 15 needs the extra 2 inches to make it the same as a 20 because of the angle of the transom. Just measure the jackplate, the gearcase will be in the same position whether a 15 or a 20.

 

[JR]

Are you sure? The transom angle varies model to model, Mfg to Mfg., so I was always under the impression the 15"'s additional setback was due to the loss of "arm" [leverage] to lift the bow on transoms designed for 20" midsections.
I could have been wrong [I have been before]. I can see your point though.
JR

 

[ziemer]

I would keep what you have for now. I just switched mine from 7" to 8 1/2", but it's a newer style jackplate from Allison that's adjustable. I would keep your 9" plate and work on learning the boat and getting the most out of your current setup.

When you do the transom upgrade make sure you use the Allison bolts that have the tab welded on the head. That way if you decide later on that you want different setback you don't have to pull the tank back out to switch. :wink

 

[citabriatom]

Thanks to all for the advice.I finished the transom upgrade yesterday.It was less fun than it looked.I was even able to come up with some new combinations of curse words(my head still hurts from walking into the engine hoist).

 

[JR]

It hurts worse now, when that happens, due to the growing shortage of hair on my head....
JR

 

[citabriatom]

Oh no!You too?!

 

[hack02]

We tell a good friend of mine he doesn't have a forhead anymore, he has a five head.

 

[whipper]

Thats better than an 8 ball!:laughing

 

[Skydog]

9" is GREAT!!!