Ok, so far I've figured out a bunch of problems on this boat, it now runs awesome, starts every time and is a delight on the water, however, I have no way to judge my speed, It used to have a very annoying buzzer on the back on the tach that went on when the key was on but not running, I pulled the buzzer off with a pair of plyers and it ended up killing the tach in the process, oops. I don't really care though cause I have always been a speedo guy anyways.
Now to the real issue, the speedo has not worked since we purchased the boat, it is an 87 Mastercraft tristar 220, air glide guage, it has the little brass fin on the bottom and works on the air pressure from the water compressing.
The previous owner had used it on a river, so when I bought it I pulled off the little fin and cleaned it out, it had some mud and bark in there. I then replaced the guage with a newer one. (The old ones had 20 mph as the very first reading on the guage.) I thought I would be good to go, However it still doesn't work, I even tried getting my brother to climb under and putting an air hose to the fin, it worked then but not on the water. If you have any ideas or have expirienced anything similar let me know. Thanks