Wow, so SI battery can actually dictate the accuracy or effectiveness of the gauge??
Wow so now my solution map will look like this..
1.) replace SI board battery, test gauge if still reading 1/4 at operating temp
2.) replace thermostat, check spark plug condition, replace if necessary, if that doesnt fix issue then back to drawing board...
in case you think these are the ramblings of a madman...im referencing my problem here..
http://m42club.com/forums/showthread.php?t=2935