Stock 502 thermostat
07-11-2005, 08:24 AM
#1
Charter Member#157
Charter MemberThread Starter
Join Date: Oct 2000
Location: Minneapolis, Mn, Usa
Posts: 1,859
Likes: 0
Received 3 Likes
on
3 Posts
Stock 502 thermostat
What is everyone using?
I had someone tell me the Merc Manual says to use 140
however mine has 165 in it.
My gauges have always read 180 when running, since day one.
What would I gain, loose or possible ruin if I changed to 140?
Also, anyone have the part # for a 140? or cross reference #
Last thought, drilling a couple 1/8" holes to allow more water passage?
I had someone tell me the Merc Manual says to use 140
however mine has 165 in it.
My gauges have always read 180 when running, since day one.
What would I gain, loose or possible ruin if I changed to 140?
Also, anyone have the part # for a 140? or cross reference #
Last thought, drilling a couple 1/8" holes to allow more water passage?
__________________
This Cat is trying to keep up with the Big Dogs
This Cat is trying to keep up with the Big Dogs
Last edited by MnFastBoat; 07-11-2005 at 08:28 AM.
07-11-2005, 09:22 AM
#2
Registered
Platinum Member
Join Date: Oct 2002
Location: Merritt Island, Fl.
Posts: 292
Likes: 0
Received 0 Likes
on
0 Posts
Re: Stock 502 thermostat
MnFastBoat,
It is my understanding that if you run a lower thermostat the ECU will read a cold condition and the engine will run very rich.
Dail
It is my understanding that if you run a lower thermostat the ECU will read a cold condition and the engine will run very rich.
Dail
07-11-2005, 11:34 PM
#3
Registered
Re: Stock 502 thermostat
I have a 1997 502 Mag MPI and just installed a new Mercury thermostat last year and mine runs 170-175. I would like to know where other 502's run.
07-12-2005, 12:02 AM
#4
Registered
Re: Stock 502 thermostat
Thanks Walgreen that makes me feel better. That makes sense because the friend who mentioned his ran around 140-150 always has a black transom when he pulls it out.
07-12-2005, 06:23 AM
#5
Registered
Join Date: Jan 2004
Location: Reedville, va. Chesapeake Bay
Posts: 754
Likes: 0
Received 0 Likes
on
0 Posts
Re: Stock 502 thermostat
My 2000 502efi 'blue motors" came with 140 deg. Thats what merc web site shows when I put my engine serial in the parts look up section.
07-12-2005, 08:18 AM
#6
Charter Member#157
Charter MemberThread Starter
Join Date: Oct 2000
Location: Minneapolis, Mn, Usa
Posts: 1,859
Likes: 0
Received 3 Likes
on
3 Posts
Re: Stock 502 thermostat
thanks Guys.
guess I will leave tehm alone and look into the the port risers haveing a partial blockage
I just do not like how the port side, and more the left bank versus the right bank, has more steam then the starboard motor.
guess I will leave tehm alone and look into the the port risers haveing a partial blockage
I just do not like how the port side, and more the left bank versus the right bank, has more steam then the starboard motor.
__________________
This Cat is trying to keep up with the Big Dogs
This Cat is trying to keep up with the Big Dogs
07-17-2005, 03:53 PM
#8
Registered
Join Date: May 2004
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Re: Stock 502 thermostat
I was having a problem with my 502s running hot (u can search for my thread). I put in 140s and they now run at 179. I am going to check the actual temp with and infared because I'm not convinced the temp senders are the correct resistance. Anyway, Merc says the 500hp (blue) takes a 140 the 502 (black) takes a 160 therm. See if you can borrow and infared.
