I removed the old puck and all the old epoxy. Sanded the area with a coarse grit paper and epoxied in the new puck.

The wire that goes to the puck, does it unhook from the old puck or do you have to cut it??

If its when you ar eruning at speed it is caused by the cavitation of air/wate under the hull not allowing a decent signal to the bottom. If its at slow speed see above posts..

new puck has a wire ...it plugs into the Gauge ...

I am looking at a 90 Baja 250 ES and the depth finder does not work. The original one in the bilge was disconnected and the seller installed a transom mounted one. I think the transom mount ones are just ugly. It too does not work. Can the transom mounted one be removed? What to do with holes? The hull is gloss red.

Looks like I have to run the new wire to the dash, almost wonderif I should just replace the gauge also and just be back to it all being new.... Thanks alot for all the help guys....