Header is hot on one motor
#1
Hey out there. I have a 382 with 700's and I have one header that is worrying me. On the port side of the starboard motor, one of the header pipes is too hot (in my opinion). I can touch all the other header pipes without any trouble after a run, but one pipe is so hot you can't keep your finger on it for more than a second or two. Is this normal? Do any other folks out there have this issue? Anything to do about it or am I just overreacting?
#2
How is the water flow compared to the others, out the tips?
What is the condition of the impellers?
SmartCraft ought to alert when one side gets too hot. Have you hooked it up to a scanner to double-check?
What is the condition of the impellers?
SmartCraft ought to alert when one side gets too hot. Have you hooked it up to a scanner to double-check?
#3
I had this problem last year so I had the impellers changed in the off season. Water flow from the tail pipes seems to be the same to the naked eye.
#5
Could be some debris caught in the main heat exchanger, partially blocking that side. Can you get to the end plates on the main HE and look inside?
__________________
Retired! Boating full-time now.
Retired! Boating full-time now.
#6
Registered

Joined: Dec 2007
Posts: 912
Likes: 57
From: Solana Beach,CA
CMI has made a new recommendation for the sweepers "headers" on the 700's. I think I have the hump hose completely closed off so all the water goes through the header? Call them to check on the latest.. Did you notice...at the miami show the new merc 525 replacement now has a header temp sensor where the header collector connects to the tailpipe....handy I thinks
Last edited by fossil fuel; 04-03-2012 at 08:48 PM.
#9
Registered

Joined: Dec 2007
Posts: 912
Likes: 57
From: Solana Beach,CA
I checked today and the lower feed from the header distribution pipe to the bottom tailpipe feed is now blocked off per merc. They want all the water to flow through the header, through the hump hose and into the tailpipe from the top. I put a 2nd hose connection for flushing on the transom. In low water pressure areas I can flush with two hoses into one motor. It matters when your strainers get sucked dry the water is not reaching the top of the upper header pipes.
#10
I checked today and the lower feed from the header distribution pipe to the bottom tailpipe feed is now blocked off per merc. They want all the water to flow through the header, through the hump hose and into the tailpipe from the top. I put a 2nd hose connection for flushing on the transom. In low water pressure areas I can flush with two hoses into one motor. It matters when your strainers get sucked dry the water is not reaching the top of the upper header pipes.



