Left leaning confusion

[waynemad]

My 84 Renken 140HP mercruiser leans left on plane even with careful weight distribution. The boat also has a hydrofoil. <br /><br />From other posts I understand this to likely be torque induced and it can be eliminated with trim tabs. Other posts have discussed adjusting the trim tab anode below the cavitation plate but the boat tracks straight. I am not crazy about spending a lot on power trim tabs for a 20 year old boat that gets used a few weeks a year up north, so they are a last resort. So my questions are:<br /><br />Will trimmming the bow up using the motor trim help?<br /><br />Eliminate the hydrofoil?<br /><br />Will adjusting the anode tab do anything in this case?<br /><br />Thanks to all in advance

 

[gaefstan]

Re: Left leaning confusion

I had a similar problem with my Bass Trophy 15' with a 50 hp ob on it. When I first tried it out after getting it back together, it leaned left although it still tracked true. I had forgotten to put in my trim bar. Also the motor was sitting too low on the transom (I had used the original mount holes which were drilled wrong). I raised the motor after redrilling, installed my trim bar and removed the 'whales tail' that was on it. Now it runs level and true. Next step is to add a setback and raise the motor just a bit more to eke out a bit more speed and smooth out the ride (just starts to porpoise in mild chop at WOT due to shifting from dual 6 gal tanks to a single 12 gal tank and moving it farther aft).<br /><br />So in answer to the ?? - <br />Trimming should help. Ensure the cavitation plate is at the appropriate level (+- 1" to the bottom - better on the - side). A deep to moderate v-bottom will ride on its side if the bow sits too low on plane.<br /><br />The hydrofoil should actually help unless it to sits too low and adds drag.<br /><br />The tab is more if you have steering problems where the torque of the motor causes it to pull or it is difficult to turn. If you're tracking true, the tab shouldn't need adjustment.

 

[Bass Runner]

Re: Left leaning confusion

Try raising the motor that might help, have you checked to see if the motor is centered on the transom? and straight up and down.

 

[Jdeagro]

Re: Left leaning confusion

You have the classic systems of a torque list. trimming the motor up should help but this may cause porpoising. The hydrofoil is likely to exagerate the problem, as it drives the bow down at cruising speeds.<br /><br />If the motor is not at the correct height (antiventilation plate even with the bottom of the boat) then the list could be more exagerated by the prop torque, motor height, and hydrofoil.<br /><br />Try removing the hydrofoil first (easiest) then check the motor height. The steering tab should not need adjustment.<br /><br />The removal of the foil will make the boat a bit harder to plane. Try Smart Tabs #ST1290-60, which will eliminate any list if you still have it. DO a Search on this forum to get mor info on Smart Tabs or go to www.nauticusinc.com

 

[cobra 3.0]

Re: Left leaning confusion

I had the listing to the left as well. I moved my battery over to the opposite side and it helped quite a bit.

 

[Jdeagro]

Re: Left leaning confusion

Cobra<br /><br />your lucky as your list was mild.

 

[cobra 3.0]

Re: Left leaning confusion

Yup.