Spring Trim tabs

[asgrinne]

Have a 89 4 Winns 205 Sundowner with a 155 Evinrude. It has an extra long shaft (read that as runs really deep in the water) IT has to cause more drag than a reg shaft I would think? <br />Wondering about those spring loaded trim tabs and if they would be a good or a bad thing.<br />Boat weighs somewhere in the range of 2600 dry.<br />Any ideas? <br />Hole shot is pretty bad, have to wide open to get on plane. running a 14.5x19 alum prop. <br />try to run it not wide open at 33 and the bow starts to come up. Playing with the trim only helps so much.

 

[snapperbait]

Re: Spring Trim tabs

Anita: You might be jumping the gun with the trim tabs. First order of buisness is to make sure the anti-ventilation plate is at the correct height in conjunction with the bottom of the hull..<br />This is the plate just above the prop. The bottom of the plate should be about one half inch higher than the bottom of the hull..This is a general starting point. Find a long straight edge "2x2 piece of lumber", trim the engine to it's running attitude, place the straight edge on the bottom of the hull & check the engines height.. If everything checks out there then try the trim tabs, or a hydrofoil like a dole-fin.. If you need to jack the motor way up, a fixed jack plate should do the trick. P.S. get a stainless prop when ya get it straight.BIG DIFFERENCE.

 

[suzukidave]

Re: Spring Trim tabs

BJB is right, if your leg is extra long it should be on an extra long transom and would hang just as deep in the water as a long shaft on a long shaft transom, no difference in drag. Measure it up like he says and see.<br /><br />What you need to figure out is if you have the right prop. You need the recommended w-o-t range for your motor and then you need to run it flat out and see what revs you get. If you can't reach the maximum recommended RPM you can improve your boat performance by using a prop with a lower pitch which will also help keep your bow down (which should be happening when you trim the motor into the transom).<br /><br />As for the "spring trim tabs" if you mean the Nauticus brand, I put them on my much smaller boat last fall and they made an incredible difference to the hole shot, ride, handlign, speed and ability to stay on plane at lower speeds. If your prop currently runs flat out about 3-400 rpm below rated W-O-T I'd recommend trying them before changing props, since they'll probably add that much rpm. Otherwise if you add them you'll probably have to reprop too. By the time I'd put the tabs on and repropped my boat it is 10 mph faster this year than last and has the same holeshot.

 

[asgrinne]

Re: Spring Trim tabs

Thanks a bunch,<br />Rats put BB back in the water last friday. Will check the difference in the lengths. <br />We tried a dolphin and it was really no difference besides took 2mph off top end. Think that since the long shaft situation it was not a good match. Strange 1st boat we have had that a dolphin fin did not help<br /><br />Yes were looking for a SS prop. The bad thing where we boat in the chain of lakes in IL, it is just horrible on props. Had low water this year due to drought. Yikes we dinged more props in one year than in 10 before. <br />Question about that, lets say you do whack something pretty good. What is any harder on the lower unit than if you whack with an aluminum prop?<br /><br />Laugh for the day--Boat is a repaint ALL BLACK. nick named:BB<br />When BB is behaving Black Beuty <br />When she is mishaving Black ****. ( think you can guess the rest.)

 

[snapperbait]

Re: Spring Trim tabs

Hope everything works out for you... About the prop thing, any impact is'nt good. The rubber hub inside the prop is supposed to abosrb the impact BUT it's not gonna absorb it all...SS at least for durability.. I run SS props and have run into almost every thing imaginable but never tore one up yet... Keep us updated..

 

[Boatist]

Re: Spring Trim tabs

I would suggest buying a depth finder with a shallow water alarm first. Runing aground can be the end to you boat motor or crew. If you plan to keep hitting things I would stay with aluminum, prop cheaper than drive shaft or gears. <br />Make sure your motor is reaching your WOT RPM's first. Trim tabs will raise the transom of the boat and get you on plane faster and at a slower speed. Trim tabs will also reduce your top speed a little and cost you a little fuel. Tabs mean the transom comes up the bow goes down so you have more wetted surface and less speed. Still for most boats it is a good thing as it inproves the ride. I do not like the spring loaded units as you have no control over them. I like the hydrolic trim tabs that you can control from the helm station. With them you can stop boat from leaning into the wind, listing from off blance load and adjust the bow up or down for best ride and fuel mileage. Best thing I ever added to my 21 foot boat.

 

[asgrinne]

Re: Spring Trim tabs

Thanks,<br />Ran into another person with a similar boat and he also is running SS. Thought we were the only goofs with a cuddy and an outboard motor. <br /><br />Just to clarify, We do have a depth finder, with an alarm. Its not running aground. Its called mobile water hazards. Debrise like logs and branches, heavens knows what else. They are never in the same place twice. We had rains and went from typical depth of 3.5ft-4.5ft to woohoo almost 5ft in some places. <br />Thanks, If you have any ideas on $$$ decent priced rebuilt props that would be great.

 

[RICKRICK1]

Re: Spring Trim tabs

Try E-BAY, have gotten several props for under $50 and that includes shipping.

 

[suzukidave]

Re: Spring Trim tabs

Boatist, I have to disagree on the effect of spring loaded trim tabs. They sped my boat up about 3 mph, not the other way round. I believe this is because they let me trim my motor out further and still have the bow stay down without porpoising and this more than offsets any additional drag they create. Maybe the effect is different for larger boats or the larger Also, adjustable trim tabs. adjustable trim tabs are certainly better if you can get'em but also 4 times as much dollars plus a ton more maintenance (it also takes only just over an hour to install the manual kind). The non-adjustable one's are gas filled shocks and I find they compensate pretty well for a displaced load. In a pinch you can also manually adjust them to account for an uneven load before you start.

 

[Boatist]

Re: Spring Trim tabs

Suzukidave, Ok there are two times when trim tabs will give beter fuel mileage. If sea conditions are such that you can not run fast enough to get up on plane without the tabs and can with the tabs. In my case my boat planes at 18 MPH with tabs retracted. Any time seas are over about 5 feet I need to run slower than 18 mph, so with the tabs all the way down can slow to 9 MPH and stay on plane. At 9 on plane do get much better mileage than at 9 mph plowing. The other point is if you need to trim your motor way under or way way out where the prop is no longer at 90 degrees to the water it will cost you Fuel and Speed. With hydrolic tabs set your speed then adjust your tabs for best ride and last adjust motor trim for best speed or lowest rpm at speed you wish to run. When the wind kicks up over 35 MPH offshore the adjustable tabs are worth the extra money. My boat leans into the wind but I can flaten it out for best and dryest ride in 10 sec.<br />As far as cost hydrolic trim tabs do cost much more but how many times have you adjusted your tab when running in 5 to 8 foot seas. I adjust mine every trip for safest and best ride. As far as maintenance goes since 1980 have had one problem. The Joy stick control got a little flakey so I replaced it with the dual switch control I wanted anyway. Also do check the fluid level once a year before our week long trip to the ocean.<br /><br />Anita, I never had any damage from floating debrie but sure could happen. I do use two different Stainless Steel props and have not put the aluminum one on the boat in twenty years. The SS props gave me about a 2 to 3 MPH improvement. I use two different pitch props but both within the WOT RPM range. In the lakes and rivers use a 2 inch lower pitch as not usually running 30 miles to the fishing banks but slowing for marinas or other boats and it gets a better hole shot. My boat is a 21 Foot Aluminum Crestliner and weights 2800 lb dry.

 

[suzukidave]

Re: Spring Trim tabs

Boatist we swim in a very different ocean and it sounds to me like you do need adjustable tabs -- I was just making the case for the manual ones in less intense conditions and especially on smaller boats. <br /><br />If it's blowing enough for 5 to 8' seas here even the ferries may shut down -- the inside of Vcr island waters have limited fetch so we don't get ocean swells, just a chop that varies with the fetch and may come from multiple directions. If it was built up to a 5 to 8' sea I doubt I would want to plane if I could. I would stay home unless I had an unbelieveably good reason (I probably couldn't even reach my boat on its mooring anyway). <br /><br />I agree that adjustable tabs would probably help in some cases, especially trying to quarter a sea into the wind, but I have yet to be out in nasty enough stuff to have reached the point where it's a problem. <br /><br />I don't notice much difference on fuel economy per hour with the tabs, but since I go faster I go further in an hour so I guess it is an improvement that way.

 

[Boatist]

Re: Spring Trim tabs

Suzukidave you are right every Boat, every Body of Water, and every Day is different. Out here on the northern California Coast normal Summer conditions is at first light winds less than 15 mph and seas 4 to 6 feet every 10 sec but by 1400 winds have come up to 25 to 40 out of the northwest, seas have increased to 7 to 9 feet with lots of whitecaps and time between swell has decreased to about 7 to 8 sec. Ofcourse there exceptions this year we had a few days with seas 3 feet every 20 seconds and very light wind all day. Our seas in summer you can almost set your compass by, they will be from 310 to 320 degrees. I think we both agree trim tabs are a good thing. I know I will never have another boat I use in open waters with out trim tabs I can adjust from helm station. They can change the ride and saftey so much I find it a must. Also a kicker motor just in case. Trim Tabs on my boat are each 24 inches wide and 12 inches deep and I love them. Best thing I have added to my boat.