CONTINUOUSWAVE

I have a 250-HP. I plan to add a temperature sensor. I haven’t found a manual or instructions.

Has anyone installed a water temperature sender in a Johnson outboard?

My 48 Evinrude had a spot for the sender in the head. It was a threaded boss directly below the spot for the overheat warning sender. Look for a blind hole that doesn't seem needed. I wired it through the harness all the way to the console where I mounted a gauge.

I have added a temperature sensor to an Evinrude 3.3-liter V6 engine, which is likely the same as a Johnson model.

What is the correct sender for a gauge with part number OMC #174090

I've searched high and low and while I can find senders, I can't find anything that suggests which one is correct for my 1999 Johnson J250PXEEN)and compatible with my gauge. [Give me] help.

Contact a local Evinrude or Johnson dealer that has been selling those engines for at least 25 years. A dealer like that will know the proper part number to order to get a sender that will match the gauge you have on hand.

Use the resources of the website SHOP2.EVINRUDE.COM to look up your engine or similar engines and accessories. You may be able to locate the information you seek on that website.

Moved to SMALL BOAT ELECTRICAL. The link from the Boston Whaler forum will be deleted.

I believe OMC and BRP use a standard sender for their gauges to keep inventory low. Any dealer should be able to supply the right one. I used Teleflex gauges and they did not include the sender so I used the standard OMC sender. On my 48-HP the sender screwed right in to the boss on the head. On my 30-HP the boss was threaded a larger size but that sender as superseded by the smaller one. It required a reducer bushing. Both worked great.

Although I am not sure you are soliciting advice on installation, you might find my narrative of the installation of a temperature sender to the power head of a c.1992 Evinrude 225-HP V6 3.3-liter two-stroke-power-cycle engine that I wrote several years ago to be useful. You can find the narrative at

Engine Operating Temperature
http://continuouswave.com/ubb/Forum4/HTML/005731.html

Later, I moved that same temperature sensor to my E-TEC 225-HP 3.3-liter V6 engine, which I believe uses a very similar power head. I illustrated the location of the temperature sensor in an article on E-TEC rigging. This might also be helpful if you are seeking advice on where to install the temperature sender. See

E-TEC Rigging Notes / Location of Various Components
http://continuouswave.com/whaler/refere ... l#location

Eventually I upgraded the engine instrumentation to NMEA-2000 networked instruments, and I removed the temperature sensor and sold it along with the matching gauge.

Another good source of information for how to install a temperature sender is found at

Small Boat Electrical Forum (Old Forum) / Wiring a Temperature Gauge
http://continuouswave.com/ubb/Forum6/HTML/000642.html