Is your bad yamaha tach round or square? The older style round gauges most often can be repaired. This is because the innards of the gauge function correctly, but either the back reflector and/or polarizer lens is damaged, and/or the front plastic screen is damaged making the digital readout impossible to see. The previous mentioned defects can be repaired/replaced. However, if the LCD is fried than there is no fixing the gauge.
www.gaugesaver.com is a yamaha repair business started by a THT member. You can send him your gauge to assess if it's repairable. If so, it costs you $50 plus shipping back and forth. If not repairable, he'll buy the gauge from you for $25 to use for spare parts for his business. He does an excellent job. He also has refurbished gauges that look brand new for sale if you don't want to send in your bad gauge.
Otherwise, your other 2 options are to buy a new one ($250-$300) or buy a used one. Ebay is a good website to find used gauges. The older style round gauge is compatible with your engine.
