120 Merc pulling to the left

[1984SportCraft]

Hello all. I just purchased a 1984 Sport Craft with a 120 Mercruiser I/O. At idle speeds (no wake around 1000 rpm), boat steers straight as a needle. When "full throttle" it seems as if you have to fight to keep it straight.<br /><br />If you let go of the wheel, the boat wants to pull left. I do not know a great deal about boats, but I cannot seem to see anything that looks out of alignment on trim. Any suggestions as to where I should start?<br /><br />Thanks in advance!

 

[Don S]

Re: 120 Merc pulling to the left

The trim tab on the back of the outdrive needs adjusted. It's also an anode and may be mostly corroded away or missing completely.<br /><br />

 

[1984SportCraft]

Re: 120 Merc pulling to the left

Thanks for the info. I believe that I have located the trim tab on my outdrive. Should it be loose enough to adjust from side to side with little to no effort? Or is it being loose that is causing my problem?<br /><br />Thanks for your help!

 

[Don S]

Re: 120 Merc pulling to the left

I needs to be tight. There is a hole in the upper housing just over the trim tab (may have a plastic plug in it). Inside is an allen headed bolt (3/8" allen wrench) that tightens it down.

 

[1984SportCraft]

Re: 120 Merc pulling to the left

Thank you so much for your help. I just love forums!! <br /><br />One final question, my trim tab is bent slightly (if looking at it as pictured above, it bends slightly to the right as it goes down). Is this expensive to replace or is a slight bend anything major to worry about?<br /><br />Once again, I appreciate the help.

 

[Bondo]

Re: 120 Merc pulling to the left

It's a Sacrificial Zinc,......... It's made to Disappear........<br />Cheap to replace,........NAPA sells them,... Available about Anywhere.............

 

[Haut Medoc]

Re: 120 Merc pulling to the left

Less than $10.00. Replace it.