I have a 88 16 ft Bomber fiberglass boat with a 90 hp Johnson. My neighbor recommends I use a transom saver. My motor has a "trail lock" bracket to lock the motor in almost full tilt position. The manual states to not trailer motor in a tilted position unless the "trail lock" is engaged. In addition, it recommends to secure the gearcase to the transom or trailer. Do I trim down on the transom saver like the other boats I see? Or should I use both the "trail lock" and run the transom saver at almost a 45 deg angle from the lower unit to the trailer? Any help would be greatly appreciated.

I would use the transom saver. It will keep the stress off your boat.

Tilting the motor prevents it from hitting the pavement over dips and other irregular surfaces.

Larger motors exert a tremendous amount of force on a transom, especially on rough roads.

It's akin to you putting a long pipe wrench on the transom, then flexing the transom.

Affix a bar between the trailer and your "wrench" and it takes most if not all the stress off the transom.

Depending, the transom saver may not hold the motor high enough to engage the trail/tilt lock.  No matter, the purpose of the trail lock is to take the strain off the hydraulic trim cylinders, but it does nothing for the transom.

A transom saver does both.

Thanks for the quick replies.  So it doesn't matter if I use the trail lock as long as I use a transom saver? Does having the motor tilted up more take away from the effectiveness of a transom saver?

Thanks for the quick replies. So it doesn't matter if I use the trail lock as long as I use a transom saver? Does having the motor tilted up more take away from the effectiveness of a transom saver?

If the lower unit is supported by the transom saver, it doesn't matter how high it is.  The primary purpose for tilting the motor is to provide clearance between the skeg and the road surface while trailering.