Riddle me this...

[FirstGear]

I have a new to me this year, a 2004 250XS. SN:OT818367. It has a Smartcraft Systems monitor. The screen is square at about 2" X 2". My question is about the temp gauge. I can start and warm up the motor, take off to a fishing spot with the temp at 147. I can fish a couple minutes. okay maybee 5. Start the big motor up and the temp reads 87 and takes the same amount of time to warm up to 120 as it does when starting cold. I KNOW the motor is warmer than the gauge is reading. Can I trust the gauge????

Thanks, David

[EuropeanAM]

Very common, ESPECIALLY when running in COLD water temps.

The Smartcraft temperature reading is QUITE accurate.

Two temp sensors (one in each cylinder head) are immersed in the coolant passageway (in contact with water traveling through the passages).

When you stop and fish, it's likely that your engine block is draining completely. Upon startup, COLD lake water floods through the engine block, bringing the actual temperature of the water to "near lake temperature" until such time as the engine again reaches operating temperature.

[FirstGear]

okay, do I still need to wait for the water temp to come to 120 before powering up knowing the engine is "warm"? It does this even in 75-80 degree water. I am not taking any un-necessary chances on this engine. Just feel silly wating for the temp to come up on a warm engine.

Thanks again.

[EuropeanAM]

I would definitely recommend waiting until the engine has reached operating temp.

BTW.... how far up are you trimming the engine when you stop? If the water intakes (ANY of them) come out of the water.... it allows for "near free draining" of the engine block (slowing down warm-up time at your next warm-startup).

[FirstGear]

I trim it up so the prop is just under water. I fish some skinny water.