150 Mariner 1996 off shore cooling

[RUSSELL613]

I just picked up this boat and motor, haven't changed the impeller yet, waiting on manual, but I cleaned up the boat and connected a six gallon tank of fuel to the engine along with ear muffs. I wanted to warm it up to take a compression test, I did not get any water out of the tell tail exhaust port. I was wondering if the lower unit needs to be submurged to get water out of it, I also tried a hose connected to the connection just below the powerhead and still no water. The heads are not overheating, only ran it a few minutes, I did gets little exhaust smoke and fumes out of the port. 1996 Mariner 150 V6 off shore.

 

[JoeBass1986]

I've heard the TStats on these are intermittent. They open and close as needed. Needs to get about 143 degrees to open them. It takes mine a couple mins to warm up and pee. Its never a steady stream unless on the lake and sometimes isn't then. Make sure impeller is good of course and if so let it run a little longer on muffs or submerged. NOT BY the cleaning port beside tell tale. Hope this helps.

 

[RUSSELL613]

Thank you, figured that the cleaning port was good, didn't like it, always used the muffs.

 

[Texasmark]

Check the Tell Tale tube back to it's origin. If it is plumbed off the T stat housings, bulges at the top of each bank, then the stat has to open to get tell tale water. As the engine warms it is intermittent as the stats open and close. My son's Merc. 150 was like that so I replumbed off the hose at the top of the engine block which went down to the byapss popoff....opens for high speed running. Result was water any time the engine was running.....no having to wait for stats to open.

 

[RUSSELL613]

Thank you, I definitely will look into that when my manual gets here, trying to get the old fuel out of the tank right now.