Mercruiser 165 riser elbow plug

gregg_a_g

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Jul 24, 2021
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I switched out a bad exhaust elbow for a newer one that I have. The difference is that my engine is setup for "reverse flow" on the coolant line, so I need to put a 1" MPT x 1" hose
fitting into one of the pipe plugs on the new riser elbow. The pipe plug is not cooperating.
Wouldn't budge, so I put a 9/16 square drive into the plug and used a small air hammer.
The edges of the plug mostly fell apart, but the plug didn't budge. I thought it might
come out without too much trouble because there is teflon tape on the plug.

Anyway, if I can't figure out how to remove it I will probably remove the riser and take it
to a machine shop. Has anyone successfully removed these plugs? Maybe drill it out
with a 1/2 or 9/16 and then a big screw extractor? Didn't know if a little heat from a
torch will help or hurt. Thanks for your ideas!
 

alldodge

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Heat will help but you would probably need acetylene or map gas to get enough heat
 

gregg_a_g

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Hi, alldodge-

The head of the plug is kind of short on meat now. So if I drill with 9/16 bit, and then get an extractor in, where do I heat? The plug or the body? I have an OA torch. I'll have to get an extractor that big.

Thanks!
 

alldodge

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Might think about drilling small holes in 4 corners maybe 3/16. Look and determine what would work best. The use a large bit to connect the holes. Basically trying to mak it square thru hole.

Use a file, drimmel or other to square it off. See if drive can be inserted.

Not heat it up slowly until red. Then try to get it out
 

alldodge

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Another idea
If u have a Sawzall with short blade. Drill hole and use Sawzall to cut several places and can use a chisel to knock pieces out
 

Scott Danforth

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heat plug up cherry red

then use can of keyboard cleaner, held upside down and freeze plug

repeat

should crack loose the corrosion
 

Bondo

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Ayuh,..... I've taken those out with my air impact gun,.....

For that one, I'd heat the plug red hot, 'n quench it with water,.....
If it don't come right out, heat, 'n quench it again,...... til it does,.....
 

gregg_a_g

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Jul 24, 2021
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Ok, so I had chores today. Tomorrow I'll get the OA torch going and heat and quench the plug first to see if it at least looks to be cracking loose a bit.
Then try to get it started turning with the air hammer and 9/16 bit pushed in hard.
If that fails, I'll start drilling and try to get a square hole to get the drive in deeper, and then heat and quench some more. This elbow really looks pretty good, so I'd really rather not by a new one yet. I guess Barr has them for about $160.
 
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