Find The Mounting Holes For Second Trim Tabs

[dag-nabit]

This is nothing new for us old dog Spartan owners, but I saw an inquiry on this just a couple days ago.

Since i was locating and opening the holes while setting up my new hull, I thought I'd snap a couple photos to help out some of the newer Spartan owners.

Sorry for the poor quality pics, I was in a bit of a hurry.

Procedure:
1. In a dim lit or darkened room shine a bright flashlight on the transom from inside the hull
2. Locate the "donut" on the outside of the hull
3. Use a sharp awl to puncture, or carefully drill out, the center of the "donut" through the hull to open access to the molded bolt recesses.
NOTE: Be careful not to drill too deep

NOTE: Lubricate threads on bolts, preferably with a non-petroleum based lubricant, before threading into hull. This will reduce/eliminate galling the plastic into the threads and will allow for easy removal.





Kevin

[patte6596@rogers.com]

Thanks for the info of trim tabs. I tried it. It works. Al Patte.

[Spartan]

Finally thank god!!! Thank you man.. Im gonna go to the shop today and do this mod for sure!!

[i2oadsweepei2]

Great info! Thanks

[patte6596@rogers.com]

Yeah it really works. Good stuff.

[orca]

Excellent job on showing people how to find thoes other mounting holes.

[dag-nabit]

Thx

[CeilidhKeith]

Thank you Kevin followed the instructions for finding trim tab holes and it worked great, i was a bit cagey about going in with a sharp pointed driver but once done it was just great.

Regards Keith

[4343]

will adding 2 more trim tabs help in the achoring the rear of the boat for chine walking?

[CeilidhKeith]

Well i done mine on friday night and sailed on saturday with it and the difference was unbelievable no more rocking about steady as it should be once you get them set right.

[4343]

did you angle the inner ones down or up? what about the outer ones?

[CeilidhKeith]

All four in line just about level with the hull.

[4343]

how do the trim tabs you added closer to the strut help? so they all shouldnt be bent up or down?

[orca]

The inner tabs (closest to the strut) are the ones that will be in use at high speeds when the boat is up on plane. Bend or adjust them down as needed to assist with chine walk, no more than 1 mm at a time and just test your runs with the batteries in the same position.

[4343]

orca, can you tell me how each of the 4 trim tabs should be? angled up or down? 1mm? and why?

[4343]

what if I take off outer trim tabs and move them in on spots closer to strut and just have the inner ones??

[orca]

You should add the additional set of inner trim tabs to help stabilize and minimize chine walk at higher speeds, 45 + mph. Alot depends on where you place your batteries and the weight of the batteries you are using.

Start with the trim tabs level with the bottom of the boat and move (bend) the inner ones first. There is alot of trial and error here.

Maybe to help, chine walk occurs when there is very little of the boat in the water and it is running on a very small portion of the hull. Once the boat gets byond this it will fall to one side and then bounces to the other side, hence chine walking.

You may also try to accelerate slower, make sure there is no play or slop in the rudder and the strut.

The causes of chine walk are many and the cures are few.

[4343]

should i bend the inner ones down or up?

[4343]

if im just using outer tabs right now, should i bend those up or down too?

[orca]

If you are using the outer tabs only you will not need to adjust thoes as they are most likely not in the water when your boat begins to chine walk.

The inner tabs, once you have them installed, should be left in the neutral position and if needed adjust down.

[4343]

if I drill out the second set of holes for trim tabs, what will the screws dig into then?

[orca]

Do not drill out the holes for the screws.... Go back and view dag-nabits post #1 of this thread.

[CeilidhKeith]

When i did it on my Spartan i did it with a pointed small screwdriver and just rotated it into the hull untill i had a hole big enough to take the screw, i then just screwed the screw and it finds the hidden threads inside and screws in, i then just had to line up the trim tab and do the same for the second hole. This task is dead easy believe me i was amazed how easy it was.The Spartan must have been molded for a second set of trim tabs to be added when made.

[4343]

should i bent down the outer tabs too guys?

[thebomber]

Do not drill out the holes for the screws.... Go back and view dag-nabits post #1 of this thread.

You may want to reread his post yourself. He said if you drill be careful not to drill to deep.

3. Use a sharp awl to puncture, or carefully drill out, the center of the "donut" through the hull to open access to the molded bolt recesses.*!**NOTE:*!**Be careful not to drill deep.

[4343]

I just want to know how you guys took out existing trim tabs, there hard to get out to bend??

[dag-nabit]

The plastic is often galled into the threads on the bolts from factory installation without using some type of thread lubricant.

It can be very difficult to remove the screws, AND, there is a risk of stripping the threads out of the plastic if badly galled.

After removal, clean all the plastic out of the threads and then lubricate before re-installation. It is preferable to use a non-petroleum based lube. 100% synthetic, bees wax, or even vegetable oil. Petroleum based lubricants may dry and crack the plastic over time.

Kevin

[4343]

what did you use to remove the screws, allen driver by hand, allen bit on drill?

[dag-nabit]

I use both, but the factory installed bolts are often too tight for my Allen bit in the driver. It is a round shaft,not hex, and often slips in the chuck when trying to do the initial extraction.

Once they are out, and I have had a chance to lubricate them, they run in and out nicely with the driver.

I have had a couple that were so tight they stripped out the Allen head, and have required backing them out 1/4 or 1/2 turn at a time with a vise grip..

Kevin

[dag-nabit]

I use both, but the factory installed bolts are often too tight for my Allen bit in the driver. It is a round shaft,not hex, and often slips in the chuck when trying to do the initial extraction.

Once they are out, and I have had a chance to lubricate them, they run in and out nicely with the driver.

I have had a couple that were so tight they stripped out the Allen head, and have required backing them out 1/4 or 1/2 turn at a time with a vise grip. Unfortunately when they are this tough to get out, the threads in the plastic are usually too far gone to reuse the original bolt.

Kevin