NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

[EarlyWood]

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Sorry vleasum...but I'm enjoying this read.
I feel your pain..
well.. not yet.
thanks.

 

[vleasum]

Re: Update....

Re: Update....

Got the head installed, machine shop took .007.

Torqued her all down, looked great.

Gotta get the rocker arms torqued correctly.

I'll let you know how it goes.

Need a new intake/exhaust manifold.

Need a new intake/exhaust manifold gasket that is....

 

[vleasum]

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

I know what you mean....

I used to read these posts and think to myself, wow that would suck to be them...

....And here I am.

To quote someone from another thread, "It's all about the fun."

 

[EarlyWood]

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

It really does suck to be "them"..
This weekend I'm planting my butt on the boat taking the thing apart, not really knowing what I'm looking for, as opposed to boating....we have similar issues... I'm awaiting your results...
get to it, slacker

 

[EarlyWood]

Re: Swapping out "exhaust" manifold on my I6 250CID Mercruiser pre-alpha stern drive.

Re: Swapping out "exhaust" manifold on my I6 250CID Mercruiser pre-alpha stern drive.

You shouldn't have to mess with the carb adjustment.

You should however do the recommended change for the water flow through the manifold. Here is a diagram of what I am talking about:

Here's how I did it on my father's boat:

What's the reason for this change of direction?

 

[Fishermark]

Re: Swapping out "exhaust" manifold on my I6 250CID Mercruiser pre-alpha stern drive.

Re: Swapping out "exhaust" manifold on my I6 250CID Mercruiser pre-alpha stern drive.

As explained to me, and I understand that Mercruiser even put out a bulletin to this affect, when the bow rises on the boat under acceleration, the water leaves the front of the manifold under the old configuration. If this continues for an extended time, (taking too long to get on plane for example), when the bow finally comes down, the water rushes back to the front of the now hot manifold causing it to crack.

With the modification, the water is always forced to the front in order to exit the manifold and the problem is eliminated.

 

[ziggy]

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

fm is correct.... it's sb 83-19. since i can't seem to fig. out how to get it to the forum. guess i'll type it since it's short...

exhaust manifold water reversal kit - MCM 165

under certain operating conditions, the exhaust manifold can develop an internal crack in the water jacket. this crack is usually in #2 or #3 exhaust port. if this condition is experienced, install Water Reversal Kit Part No. 60252A3. this kit reverses the water flow thru the exhaust manifold. water (from the engine) enters the rear manifold end cap and flows forward. the water exits the manifold from the front end cap and flow (via a hose) to the exhaust elbow. follow instructions, that come with the kit, for installation. water reversal kit 60252A3

 

[bigblocksarefun]

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

http://www.marinepartsman.com/Mercury-Marine-service-bulletins/MerCruiser/1983/EN_19.PDF

 

[vleasum]

Thats the Ball Game...

Thats the Ball Game...

Got it done! Not bad, pretty much the whole summer this year in Wisconsin working on my boat!

She's up for sale and I have people interested! Booyah.

 

[EarlyWood]

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

Re: NEW PROBLEM!! OVERHEAT!! Swapping out "exhaust" manifold on my I6 165hpMercruiser

After all of that, you're putting her up for sale????
Did you solve the problem?
I got another tow-in Sat nite..at least it was a full moon