So here's what's going on. I just got my motor running again and one of the upgrades was a crossover (w/ bypass) and thermostat (it didn't have a thermostat in it before). I had never seen any water temp reading on the gauge when I bought the boat until I got it running again. On Saturday Everything appeared to be functioning fine with the temp when we where breaking in the cam while the boat was on the hose sitting on the trailer. After we got it broke in we took it for a test drive for about 15 minutes and the entire time we where out on the water the temp gauge never showed any temp at all. It's got me baffled that I would have temp on the hose but off the hose there's nothing reading on the gauge.

Any thought's to why this would be happening. I'm a bit concerned because of all the "sludge" that was in the top of my motor when I tore it down before I started all the upgrades I did to it recently (the oil on the dip stick was clean and what I drained out was not milky). I'm assuming that all the sludge I found when I began this project was caused because there was not a thermostat being used and I don't want to go through that again so I put one in when I put the motor back together (the thermostat is a 142 degree thermostat and came with the crossover kit that I bought from Cp performance). Any help would be greatly appreciated! Also, has anyone had any issues with their tachs reading about 1,000 rpm off after swapping out their thunderbolt ignition for msd ignition? If this helps, the tach is a vdo "blueline" series tach and the msd box is marine that uses the seperate rev limiter box. Thanks again!

I am sure that you have checked the wiring. Out of curiosity have you noticed any movemnet of the gauge needle when you turn on the ignition? I believe that the needle will move slightly, also check around on the net bur I believe that to check youy gauge to see if it is working that you momentary ground out the sender wire and the gauge should peg out. Hope this helps.