Sealed exhaust relief ports

Hi guys, new to this forum, here it goes!!

I recently purchased a '91 135 2.0 BlackMax to upgrade from a 90 horse '89 mercury.

Upon arrival of the motor i noticed the upper relief vents on the midsection appeared to be sealed. Is this normal for the 135?
It seems odd, as if the holes were never drilled.

Another thing I did not get a chance to test it yet, bu the previous owner told me it had an overheating issue, could these un-drilled vents be causing the problem (it shouldn't)

any input is greatly appreciated.

regards,

Chun

Quote:

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Originally Posted by Chundriss

Upon arrival of the motor i noticed the upper relief vents on the midsection appeared to be sealed. Is this normal for the 135?
It seems odd, as if the holes were never drilled.

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1. Yes
2. Start with a water pump kit, the impeller should be replaced every spring. This motor will not discharge from the tell tale normaly until it reaches operating temp and will discharge on a cycle as the t stats open and close.

It should have some sort of idle relief , thats odd.

Also check or replace the t stats.

As for the cast in exaust port being closed near the underside of the pan....Mine are also closed and do not effect anything. They were used on prior motors, and never changed the castings for the mid housing.They rerouted the exaust through a rubber hose under the cowling as a updated version from what I found. Hope this helps. Also, mine is a 93 200.

Quote:

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Originally Posted by laser380

As for the cast in exaust port being closed near the underside of the pan....Mine are also closed and do not effect anything. They were used on prior motors, and never changed the castings for the mid housing.They rerouted the exaust through a rubber hose under the cowling as a updated version from what I found. Hope this helps. Also, mine is a 93 200.

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On a lot of motors the relief holes will be open to help with exhaust relief if a motor sets too deep in the water, like a short shaft motor. One of the things that usually accompany these relief holes is a small 3/8" hole in the back of each exhaust tube facing the relief holes. I have seen this hole about an inch from where the exhaust tuner bolts to the bottom of the exhaust plate.

Best wishes, Carter Powell

Thanks for ample explanations; this motor will go on a 18' runabout. just need to finish another project (Nissan Pathfinder) before I can start working on the motor. I'll keep you guys updated!!!

Thanks for all the help.

Regards,

Chundriss