How much setback?

[BARRY J]

How much setback should I have with a 2003 and a 200 Super Mag short shaft? Went run it yesterday. Another 2003 was there and got 5 mph faster than I do with my prop. He has less setback than me. Just wondering if I have too much.

[AllyFishing]

Good question!

[F2008]

I can only take credit for posting it, not the content. But it originates from a fairly reliable source.

Unfortunately, there are no simple charts or graphs that will tell you exactly what offset will work best for you.

When considering transom offset, we are looking at a specific characteristic of the boats’ performance. We know the offset is correct if:
The boat runs at the proper 4-6 degrees of positive bow attitude
The motor trim angle is neutral or slightly negative, relative to the water
The boat carries the desired load without exceeding the above parameters
Steering torque is not excessive. (Nearly neutral at high speed is desirable)
If the above items are not satisfactory, additional transom offset may be the solution.

If the boat requires a high bow attitude to attain its best speed, the motor is too close to the transom.

If the motor trim angle is positive relative to the water and throwing a rooster tail higher than the motor, additional offset is needed.

You should test other props before going to the expense and trouble of changing the offset. A prop with more lift may cure the problem.

Do not get the impression that extra offset automatically produces more speed. Let’s examine the situation of rigging for maximum top-end with a light load. Relatively speaking, a small amount of offset provides the proper lift characteristics.
Assume that we have the desired running attitude of boat and motor. If we move the motor farther to the rear in this situation, odd things happen. When trimmed to the proper attitude, the gear case now goes to a deeper position in the water. By exceeding the ideal amount of offset, we are now burying the gear case when trimmed properly.
Picture the rear edge of the running pad as the fulcrum point of a teeter totter. The higher we trim the bow the deeper the gear case goes. Obviously, the boat will run slower. Think about it!

[Hullbilly]

14.5 should get you close with a 2.5 motor. Of course, this depends on how big of a guy you are. Setback is a way to use the weight of the engine as a counter weight. Therefore, the bigger you are, the more setback that can potentially help your setup.

There are many things that effect top speed on an allison besides prop and setback. Engine height is a big one that comes to mind. If you've got your motor too low, that could easily be 3 to 5 mph.

Be carefull and good luck!

[Props4u2]

13 1/2 to 14" is where the 2003's perform the best with trolling motor, 3/batteries and two people. You may get by with a little less with one person and no trolling motor, I don't know as all of them I set up were for fishing partners.
You should see 85 gps with a good prop on your 200 Super Mag tournament ready, two people.

[BARRY J]

Thanks guys. Does too much setback cause bad handling? I have 16 inches setback now. Will get it to 14 this week before it goes back in the water.

[chad202]

Barry, we need to hook up. If ur running 16" and ur below the pad that's ur problem.

[AllyFishing]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Props4u2 &raquo;</td></tr><tr><td class="quote">13 1/2 to 14" is where the 2003's perform the best with trolling motor, 3/batteries and two people. You may get by with a little less with one person and no trolling motor, I don't know as all of them I set up were for fishing partners.
You should see 85 gps with a good prop on your 200 Super Mag tournament ready, two people.

</td></tr></table>


Lee,
If you were to put a 2.5L 225 PM on a 21' 2+2 how much setback would you use?
Thanks
Craig

[Props4u2]

Craig,
The last 2.5 that I set up on a 2+2 was a 225x. I set it back an extra two inch's, lifted and ran great with all equipment and two 200 pounders.

[AllyFishing]

Hmmmmm....thank you for that reply Lee!! That's what I was thinking. Remove the wedges and add 2" spacers. Done deal! The weight of the 225X will help carry the bow set back a bit?

Your help and advice is greatly appreciated!
Craig

I'll let ya know how that works!

[AllyFishing]

This is a great post, I hope it helped you out BarryJ as much as it did me. Thanks guys for all your great advice.

[Ally03 200xs]

What prop were you using to see 85 gps with a 200 Super Mag tournament ready and two people?

[Props4u2]

Neil,
A 28 Lightning ET 3-blade will do the trick.

[Props4u2]

Cool video Neil !!!!!!

Looking good.

[Ally03 200xs]

Thanks Lee, I never knew a 28 ET could carry a load that good. How is the FNR prop coming along?