Trouble planing out

[Bass Runner]

Re: Trouble planing out

I don't know what dia. or pitch prop you have but i'm running a 16' boat with 5' beam with a 70hp Johnson, im running a 13" dia. with 19 pitch with no problems it just jumps flat and flys with no trim. It may be your boat.

 

[cbrevelle]

Re: Trouble planing out

My boat is 1980 Tracker III with a 70 hp Johnson. The prop on it now is a stainless steel 13 3/8 x 17". I fooled around with the trim yesterday and noticed that the cavitation plate, when in line with the flat bottom of the boat, is exactly even with it in terms of height. I also noticed that that that same position, I could put the pin in at the 3rd (center) hole at the transom yoke. I have been running the motor trimmed "in", towards the boat, all the way in order to try to prevent the bow from rising so high. Could it be that I had it trimmed in too much and that was causing the boat to ride low at slow speed and have trouble planing?<br />Also, I've been checking out the various smart tabs and hydrofoil stabilizer advertisements. The hyrofoils I looked at (Stingray and Tiger Shark) seemed inexpensive and easy to attach. Has anyone had any experience with either, or can recommend another? Thanks.

 

[rickdb1boat]

Re: Trouble planing out

Put the pin the hole nearest the transom and see what happens. That is the advantage to power T&T. You start with the motor tucked in and then when you start to get on plane, gradually trim the motor out for best performance. Like was said, you really don't even need the pin with T&T. I'd still try a doel-fin and see what happens. Bet it jumps up quicker and gets on plane faster, as well as stay on plane at slower speed. You will have to adjust you trim habits somewhat to take advantage of this. In other words, you may not need to tuck it ALL the way in when you take off. And you may wind up trimming it out further that you used to, when at speed.

 

[Jdeagro]

Re: Trouble planing out

Orleans;<br /><br />Do a limited search (no more than 30 days or you will have more reading than you can dela with) on both Smart Tabs and Hydrofoils on this site.<br /><br />To DHadley's point - the faster a two cycle motor runs the more efficient. It all has to do with exhaust pressure. What restricts them from running faster (RPMs) is generaly the intake capasity (Carb). Obviously the load is a restriction, which in the case of a boat will directly relate to the prop size and pitch.

 

[Jdeagro]

Re: Trouble planing out

By placing the motor as close to the transom (down) as possible, you are using the prop to lift the back of the boat, and obviously pushing the bow down. In this possiton the prop angled up and although it lifts the stern, it is slipping the outside edges of the blades and loosing efficiency. The most efficient angle is perpendicular to the surface of the water, and tilting it one way or another comprimises the forward thrust. If the motor has electric tilt and trim then you can take advantage of the trim the help the boat plane, and then trim back to perpendicular to maximize efficiency. Also once the boat is on plane you should not need to lift the stern (unless the boat porpoises).<br /><br />If you do not have tilt and trim, then you will need to:<br />1) try to find a best case compromise in motor position.<br />2) add additional planing device to the boat so that the motor can be set perpendicular.

 

[quantumleap]

Re: Trouble planing out

Dhadley- Thanks. I always though it was better to be a little "underpropped" than to lug the engine.

 

[Dhadley]

Re: Trouble planing out

Youre welcome quantumleap. Hope that helps. There's a lifetime of learning with this stuff.<br /><br />I really dont care for the term under and overpropped but, like I said thats the common term. I really only change props to gain rpm as a total last resort. I like to gain rpm by reducing drag. That includes the gearcase and the "wetted surface". <br /><br />I guess that comes from the "good ol days" when we only had a couple of really good race props to choose from. You picked one and made the boat fit the prop. Now that was a steep learning curve!

 

[cbrevelle]

Re: Trouble planing out

Thanks for all the imput... I ordered a Stingray hydrofoil stabalizer yesterday and will see how it works out. It seemed to be the cheapest fix if it'll work, and if it doesn't, it's no big loss ($50) and will be easy enough to remove. I considered the smart tabs but don't have a lot of room at the transom and don't relish the idea of drilling holes in the boat if I can help it. I'll let you folks know how the Stingray works out once I get them and try them out.

 

[Jdeagro]

Re: Trouble planing out

You should plane somewhat easier. If the motor allows the Hydrofoil to run at or below water level, the boat will bow steer and cruising speeds and run slower at top end. In corners you'll need to back off the throttle or the bow will dive. <br /><br />When your ready, try smart tabs

 

[Bass Runner]

Re: Trouble planing out

I just had a thought, i used to have a texas maid that did that same thing, i changed about everything trying to get it to plane faster to no avail trim tabs included, i hate to tell you what it was, hope you are sitting down, here goes, The floatation was soaked up with water, i pulled the floor and removed the floatation, reinstalled a new floor and new floatation foam and the thing was a rocket after that. Sorry

 

[Solittle]

Re: Trouble planing out

orleans53 - Bass runner may be on to something. It wouold be easy to check by getting the boat weight. That should tell you if you are waterlogged or not.<br /><br />You should fly with a 70 on a 16' unless the motor is sick or you are pushing a ton of weight.

 

[cbrevelle]

Re: Trouble planing out

Thanks for the thought, but I know who I got the boat from and this guy kept it covered always and under a roof. It's an aluminum boat and it has always been dry as a bone. I doubt very seriously that any water could be trapped, or at least not enough to make a whole lot of difference. I think the fact that it has a center (double) console and the motor is so large, that when sitting two in the rear, it's just rear-heavy. It does fine once it's on plane (it does fly). I just fish in areas with lots of obstruction just under the surface and I have to move pretty slow. I just want the bow to come down some so I can see better.<br />I did try this weekend putting the pin into it's lowest (closest to boat) position and it seemed to do OK at slow speeds with the power trim in all the way. Maybe the fin I ordered will come in this week and it'll do even better. <br />In any case, I've been having fun fishing in the mean time. Caught a bunch just this morning!