2003 mercury 150 saltwater carb motor running hot at full speed...HELP

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

Is there a water pick up screen somewhere that may be clogged? THANKS

 

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

bump

 

[Chris1956]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

Well, If you left the motor in the water, barnacles can get into the water intakes. They used to clog up my Mercruiser intakes every year, and I am in NJ where the water is cold most of the year. Florida would have bigger and better critters to clog stuff up.

 

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

Thanks for the reply! My boat stays on the trailer

 

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

Well I installed a water pressure gauge and my pressure is 5 psi at idle and 12 psi at full throttle temp is still 180 at WOT. Just purchase a mercury manual and it says over heat alarm comes on at 240 and off a 210 and my seloc manual says the same so Im guessing 180 degrees it normal operating temperature for this motor even though both of my mechanics say 180 is to hot

 

[Dukedog]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

12 is border line ona production motor. If ya fish any kinda shallow water its gonna run sand/junk through tha pump over time. Just sayin'.....Get a heat reading gun and check "true" temp. Most factory type gauges are not so accurate. And also there are FOUR nuts holdin' tha tuner on. 2 on each side. Not just two..........Don't let 'em bs ya.

 

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

thanks for the reply!! I bought a laser temp gun and both cylinder heads and engine block temp readings were just about dead on with the gauge at idle for 10 minutes the temp was about 130 degrees on each cylinder which sounds about normal to me with gutted thermostats. I dont know what to think lol. The motor is nice and quite and runs like new. I guess Ill run it the way it is. Also water temps in florida are close to 88 90 degrees so I would expect the motor to run a little warmer.

 

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

I also put my stock 17 pitch prop (Ive been running a 21 pitch prop the boat definitly likes it but it only turns 4800 rpm) back on and at WOT temp was about 170 to 175 max but the 17 pitch prop is a dog with my boat. I can run 5500 rpm with the prop (which is recommended from merc)

 

[merc150]

Re: 2003 mercury 150 saltwater carb motor running hot at full speed...HELP

anybody else running 180?