Where to install clear tubing

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nickmo

Petty Officer 2nd Class
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5.0 liter TKS Alpha 1 Gen 2 drive.

I've been dealing with a high speed overheat for a while now. According to the Mercruiser Bulletin, to test for air in the system, install a clear hose from the tstat housing to the starboard riser. Others say install the hose after the power steering cooler and before the tstat housing. That is a much larger hose and would be harder to find a clear hose that size. Has anyone done this and how?

At the beginning of this season, I changed the impeller and applied permaseal to the lower gasket as per the bulletin. It ran cool all season till now.

BTW Manifolds and risers are 1 year old. Tstat new at the beginning of the season. No restrictions in system. Raw water cooled.
 
alldodge

alldodge

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Most add a short piece of hose to one end of the main hose. The clear piece just needs to be long enough to show if something is happening.
 
Bt Doctur

Bt Doctur

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At the beginning of this season, I changed the impeller and applied permaseal to the lower gasket as per the bulletin. It ran cool all season till now.

Then change the impeller and gaskets and report back. I use Permatex Aviation liquid for those gaskets, You dont list a location so are barnacles an issue.
 
N

nickmo

Petty Officer 2nd Class
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Apr 2, 2010
Messages
117
Bt Doctur said:
At the beginning of this season, I changed the impeller and applied permaseal to the lower gasket as per the bulletin. It ran cool all season till now.

Then change the impeller and gaskets and report back. I use Permatex Aviation liquid for those gaskets, You dont list a location so are barnacles an issue.
Click to expand...

The boat is wet slipped. Location is Ocean County NJ. The lower drive and intake area are free from barnacles because I clean them every month or so. Are you saying they can grow beyond the intake holes? I don't have a trailer for this boat so I'll pull the drive and take a look when I pull the boat in a week or so.

This high speed overheat has been an issue for a couple of seasons now. I thought I had it solved this year.
 
JoLin

JoLin

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nickmo said:
5.0 liter TKS Alpha 1 Gen 2 drive.

I've been dealing with a high speed overheat for a while now. According to the Mercruiser Bulletin, to test for air in the system, install a clear hose from the tstat housing to the starboard riser. Others say install the hose after the power steering cooler and before the tstat housing. That is a much larger hose and would be harder to find a clear hose that size. Has anyone done this and how?
Click to expand...

I'd like to know this, too. The same issue recently started on my starboard engine. I'm going to replace the Alpha water pumps anyway, but would like to check for air before I lay the boat up for the winter. I agree, the cooler-tstat housing hose is big and I don't know where I'll find clear hose and connectors to tap into it.

Do you by any chance have a link to the Merc bulletin about using a hose to the starboard riser? I'd like to see that.

My .02
 
Grub54891

Grub54891

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The barnacles will work their way up the intake hose as far as they want to go. Nasty critters.
 
N

nickmo

Petty Officer 2nd Class
Joined
Apr 2, 2010
Messages
117
JoLin said:
I'd like to know this, too. The same issue recently started on my starboard engine. I'm going to replace the Alpha water pumps anyway, but would like to check for air before I lay the boat up for the winter. I agree, the cooler-tstat housing hose is big and I don't know where I'll find clear hose and connectors to tap into it.

Do you by any chance have a link to the Merc bulletin about using a hose to the starboard riser? I'd like to see that.

My .02
Click to expand...

This is it. www.boatfix.com/merc/bullet/95/95_13.PDF
Sorry tried to copy and paste.


Guess it did work.
 
JoLin

JoLin

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Interesting that the troubleshooting procedure leads back to the water pump as the only cause for air bubbles in the cooling hose. Not sure if that's always true, but the info is valuable anyway. Thanks much- that helps
 
N

nickmo

Petty Officer 2nd Class
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Apr 2, 2010
Messages
117
I took the hose off that runs from the t stat housing to the starboard manifold. It is 1 1/4. I picked up a piece at the hardware store, but found that the outside diameter of the bought hose is 1 1/4. The inside diameter is 1 inch which won't fit. I've been everywhere and can't find 1 1/4 ID hose. I haven't even tried finding something big enough to fit the hose coming from the PS cooler. Has anyone done this?
 
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