How hot is to hot
#1
Charter Member #232
Charter Member
Thread Starter
How hot is to hot
I have been running my boat for the summer and the temps have been at about 150 degrees all summer. Last evening I ran up for dinner with some friends and the boat was running at about 180-190. The water temp this week was warm (about 78-80 degrees). Is it the warm water temps causing the problem or do I maybe have another issue to look into. These are 420hp 454's and they both are kind of doing the same thing. The temp held steady no matter what speed I ran.
Jon
Jon
__________________
Put your best foot forward!
Put your best foot forward!
#2
Platinum Member
Platinum Member
Do you have the Merc 143 degree thermostats? My 454 370 HPs used to stay dead on no matter what the conditions. I wonder if you flow is restricted or maybe your impellors are weak. Are both engines the same? Any changes to the original Merc water system?
#4
Charter Member #232
Charter Member
Thread Starter
New water pumps this year and they are both doing the same thing. They just started this yesterday. That is why I was thinking the lake water was so warm causing this. Everything is totally stock.
__________________
Put your best foot forward!
Put your best foot forward!
#5
Registered
Jon, change the controls, that is t-stats. be sure your flow is good and be sure your sea strainers are clean. say hi to Kurt.
#6
Charter Member # 55
Charter Member
My engine water temps never changed at all in my 525SC, no matter what the lake water temp was. Idle and cruise was around 145* and WOT was just under 160*. It had the same cooling system as the 420.
#7
Charter Member #232
Charter Member
Thread Starter
I will try and get some time today to take a look at it. I just find it so odd that this happened all of the sudden and with both engines.
__________________
Put your best foot forward!
Put your best foot forward!
#8
Registered
iTrader: (3)
Join Date: Aug 2007
Location: Sandown, NH - Sebago Lake Region, ME
Posts: 2,960
Likes: 0
Received 6 Likes
on
6 Posts
Are those engines fresh water cooled? I dont think the water temp being maybe 10 degrees warmer then normal would account for a 30 degree variation in running temp. As others have said I would check your flow rate starting with the strainers and the impellers
Jim
Jim
#9
Charter Member #232
Charter Member
Thread Starter
They are raw water cooled. I am going to dive into the water today if I have time and check and see if the water pick ups got clogged with weeds then work my way from there.
__________________
Put your best foot forward!
Put your best foot forward!