i had a small white spider growing in my 1998 flsts speedo gauge. i tried to propane him dead,then i tried the truck exhaust,that didn't work either just made a big mess of the inside.finally i used a magnifying glass and burned him with the sun.he was dead but i didn't like the mess i made of the inside!i finally ran the kitchen sink full of hot water and dish soap and submerged the whole gauge till the water seeped into everywhere and i swooshed it around back and forth.kind of drastic huh!! i rinsed all the soap out of everywhere and tiped the whole gauge all up and down to get most of the water out,the rest i used a hair dryer blowing into the back of the gauge to dry the face plate off.let the gauge and printed circuit dry real good and plugged it back in.been working ever since.would not recommend this unless you are really desperate. the spider had built a small web right over the digital readout for the miles travelled and it was blocking two digits of the readout.if you want to seal the gauge up a small ball of plumbers putty will seal any opennings up in the back where the moisture enters but i did not do this because i figured the gauge had to breath based on changes in athmospheric presure or humidity.you will do more harm than good trying to take the glass off the gauge.