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Removing spark plugs

C

carlnap

Contributing Member
I have a mercruiser 5.0 mpi 20

I have a mercruiser 5.0 mpi 2003 my plugs are under I believe are the risers. They are in a pain in the @#$ spot to get with my rachet and socket. Is there a special tool you guys use to remove the plugs. I used a extension to a 13/16 socket and the angle wasn't totally correct.Any reccomendations??
 
Carl:

I use a mirror on an

Carl:

I use a mirror on an extension rod and an articulated adapter on my ratchet; looks like a U-joint. You can also use a wobble extension that provides a little bit of an ange to move the extention.
 
"Some guys use a plug socket t

"Some guys use a plug socket that has a hex on the end, and then put a box end wrench on the hex.

I have never owned a Merc engine that I could not get to easily with a standard plug socket and drive extension, but I guess there are quite a few out there.

Guy, is that your 4.3 that you have to use the wobble adapter with? Just wondered because the 4.3 I had did not need that at all. Vortec heads, right?

Rod"
 
"[b]"I have a mercruiser 5

""I have a mercruiser 5.0 mpi 2003 my plugs are under I believe are the risers. They are in a pain in the @#$ spot to get with my rachet and socket. Is there a special tool you guys use to remove the plugs. I used a extension to a 13/16 socket and the angle wasn't totally correct.Any reccomendations??"

Ayuh,.......

Those Big Black things are the Exhaust Manifolds,... The Risers are bolted to the Top of the Exhaust Manifolds.......
And,......
If you were to use a 5/8ths" Socket,.....It'll work better........
Chevy hasn't used a Sparkplug with a 13/16" hex in a Lifetime or 2.........

Once you get a 5/8" socket,.... Grind the Corner down on it, the corner out by the Square Hole End....
And,......
Using a 3/8" Drive set will also give you alittle more Cheat Room......."
 
Rod:

Non-Vortec 1987 heads;

Rod:

Non-Vortec 1987 heads; I use the articulated adapter w/permanently attached socket for GM plugs on cyl. nos. 1&2 to reduce busted knuckles. Plugs can be removed at any angle with it--bought it in 1980 and used it on almost every dang GM car I've owned due to the "NO CLEARANCE". Plugs 3-6 only need a standard plug socket. I bought the wobble extensions by accident and they are great when you need a little angle.

Bondo:

I like your ideas!
 
"Just a few words of encourage

"Just a few words of encouragement. I got through doing this to two 5.7L engines just this week. The plugs in this boat probably hadn't been changed in ten years and were completely rusted to the block.

I used a mirror at the bottom of the engine to help me on the first side. I ended up breaking off just about all of the old spark plugs with the 5/8" spark plug socket. I then used a 5/8" short socket with an extension handle to break them loose. It turns out this makes things pretty easy if you don't freak out about breaking off the plugs. I also found out the hard way that I should stretch a piece of canvas under the side I was working on to catch everything that I dropped. I spent about an hour on the first plug fishing in the bottom of the boat with a magnet on a rope.

On the other engine, I got smart and got a can of PB Blaster and sprayed massive quantities on the plugs and let it soak overnight. Also on this side, I found out I could just feel where the plugs were and did not need a mirror or light. On this engine, I was able to get most of the plugs out with the spark plug socket. I did have to break a couple of them since it was too tight to operate.

The plugs that I took out were regular automotive plugs. I don't know if this added to my problems or not. It was funny that on the first engine, two of the plugs had been changed and had the correct marine plugs. My guess is that whoever started this process the last time saw how hard it was and said screw it."
 
Tim
Whats the differance betw

Tim
Whats the differance between AUTO & MARINE spark plugs?? I am about to install a 5.7L long block in my 1989 Slickcraft and purchased AC Delco auto plugs. Should I be using something differant???
Thanks
Bob
 
Marine plugs are made with ste

Marine plugs are made with steel that is more corrosion resistant. Other than that they are the same. I have used automotive plugs in marine engines that are berthed in ocean marinas. With any spark plugs it is a good idea to use anti-sieze on the threads of the plugs to keep them from getting frozen into the head with rust.

Note that automotive hose clamps that are stainless are of lower grade stainless than ones designated for marine use.
 
"Once I barely loosen the spar

"Once I barely loosen the spark plugs I give each one a good shot of compressed air to blow out any rust or dirt particles from the plug area. I also use a dab of "never sieze" on the replacement plugs.

When spark plugs are hard to remove, after getting them out, consider using a "thread chaser" with a coating of heavy grease to clean the excessive carbon and debris from the threads. The grease keeps the crud from falling into the cylinders. Note: It is not a "thread tap" so it won't enlarge the threads."
 
"Marine plugs are made wit

"Marine plugs are made with steel that is more corrosion resistant. Other than that they are the same."

Are the heat ranges the same for a marine application where the engine T'stat is 140 F. vs. a truck w/a 195 F. T'stat?
 
"I believe Manufacturer's

"I believe Manufacturer's recomendations for plugs are based on the individual engines in STD format but I believe you can play with your heat ranges a bit depending on your individual situation.

If you have a well worn 350 in an old chugga cruiser and you putt around all day your plug heat range requirement can be a bit different to the new 350 in your ski boat that funs on high octane fuel and spends most of its life on the high side of the tacho.

At least thats what I was always told when I was a young warthog.
happy.gif


Cheers
Peter C"
 
"[b]"Whats the differance

""Whats the differance between AUTO & MARINE spark plugs?? I am about to install a 5.7L long block in my 1989 Slickcraft and purchased AC Delco auto plugs. Should I be using something differant???"

Ayuh,......

Different,..... Donno, You didn't say Which 1s you bought.......

Chevies Love AC plugs,+ That's All I run in a Chevy......
And,.....
With the ACs, the Automotive plugs used up to the introduction of the Vortec heads are R43T, Vortec heads need the Longer plug, which I believe is R43TS.....
And,.....
The Marine equivalant is the MR43T,+ the MR43TS,....... The M in the part # means it has an Alloy body, rather than a Steel body......"
 
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