Expert: Jeff Grigg - 1/16/2008

Question
I have an '01 (model J25TELSIS) 25 hp Johnson that does not have a trim tab.  Internet diagrams show one, but there is no sign one has ever been present, instead there is a flat anode on the top right side of the fin directly above the prop.  The boat wants to turn left when running wide open.  The weight in the boat is balanced and the motor is almost center of the transom (it may be 1/2 inch too far left).  What can be done to correct the steering?  It is almost impossible to run very long.  Can a trim tab be added?  Is the anode used for adjustment?  Is it simply because motor is not dead center?  One last piece of information there is a housing on the gearcase that has rubber guides in it.  I can tell there is a larger gap on the right side than the left.  Don't know if that means anything.

Answer
Your motor should have a trim tab, you will need to use it to counter the torque. You can pick one up at your local dealer. I would recommend you recheck the mounting of the engine. It must be perfectly in the center of the bottom and at a perfect right angle. If it is tilted to the side it will affect handling. If your engine is already 1/2" off I would say someone was sloppy in mounting it. Seal any bolts with some 3M 5200 sealant.
Use the bottom of the boat for all measurements, not the sides or deck.
When you check the mounting try and get the anti-ventilation plate even or slightly below the bottom of the boat. It can also be a little above (about1"). If too high it will also affect the torque.
Post back with what you find.
Jeff