Re: Temp guage for 200 evinrude?
Temp gauges can be installed on your engine and they measure one of two things depending on the sensor you choose and where it's mounted. If the gauge comes with a sender that screws into a port in the water jacket, it measures water temperature in the block. If it has a sender that mounts to the cylinder head using a headbolt, it is technically a cylinder head temperature sender. Either way, the sender must match the gauge you buy. Teleflex and Faria both offer them. DO NOT buy a gauge calibrated 120 - 240 degrees as these are for I/O's and Inboards. Outboards run much cooler. Although there aren't many around any more, an outboard gauge should read 60 - 220 or so. Most outboards at idle run in the 120 - 140 range and drop somewhat when the bypass valve opens at higher speeds. Many outboard gauges are now calibrated "C - N - H" (cold, normal, hot). Ideally on your engine you should have two senders, one for each head and switch that allows you to alternately monitor both sides of the engine. Monitoring one side is of little help if its the other side that's running hot.