J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Adding a temp gauge - 2GMF with B-panel

I agree on the metric thread analogy for the temp sensor. Even though the block was made by General Motors (hence the 2GM moniker), the balance of the parts are designed & built by Yanmar using metric standards. Both standards are used on the engine, although the fasteners are predominantly metric. The socket set I keep on Rhapsody has both metric and SAE sizes to accommodate both. I highly recommend picking up something like a 24 piece SAE/Metric socket set and leaving it on the boat with other "emergency" tools. These have saved my bacon more than once when a needed repair was made underway, or while cruising.