Trim Gauge/Sender Question

Recently my trim gauge stopped working. I replaced the gauge with an OMC gauge I found on Ebay. After connecting the new gauge I verified that the sender was still good. For the most part, everything appears to be working again with one minor issue. The needle in the gauge will only go up about ¾’s of the way to the top. Additionally, when I trim down the needle reaches the bottom of the gauge before the motor is fully trimmed down. Is there some way to calibrate the gauge/sender so that the needle in the gauge accurately reflects the position of the motor? I have checked the sender to be sure that there are not any obstructions that could be messing with what is displayed on the gauge. Before my old gauge died, everything worked fine. Maybe I should try my luck with a different gauge. The motor is a 1978 140 hp Johnson. Please offer suggestions.

Re: Trim Gauge/Sender Question

Depending on what engine is in question,there should be two locking screws on the sender unit that afix through slotted holes which allows for adjustment of the sender position