Trouble getting at the spark plugs properly. Mercruiser 165 alpha one 3.7l

[H@ystack]

I'm trying to put new spark plugs in this engine. The angle is so odd and with parts of what i believe to be the coolant system in the way, I cannot get a straight shot to the plugs (especially stern side). I was able to get one out with hundreds of 1/64ths turns on the socket, but that clearly isn't practical. Am I missing a good tool out there or something? I've tried 3 extensions, no extensions, and 2 spark plug sockets.

I'm hopeful someone knows what I'm trying to describe and has experienced this or there is just some magical socket i can grab that I've never heard of.

 

[Bt Doctur]

you need to grind/machine away the hex part of the socket and use a 3/8 ths universal joint

 

[stonyloam]

You need to use a box end wrench on the hex end of a spark plug socket. Slip the socket over the plug first then the wrench on the socket. Yeah #4 can be a pain! You might be able to get a ratcheting box wrench in there, don't know, never tried it myself.

 

[H@ystack]

You need to use a box end wrench on the hex end of a spark plug socket. Slip the socket over the plug first then the wrench on the socket. Yeah #4 can be a pain! You might be able to get a ratcheting box wrench in there, don't know, never tried it myself.

Thanks so much. I knew it was just a concept of "needing the right tool". Even a slight angle and you're snapping spark plugs left and right. I've worked on a few older engines. I had a straight 6 1984 F150, and it was a straight shot to those things, so this a rather new experience, and seemingly such a simple fix I couldn't wrap my head around.

 

[stonyloam]

Just don't drop #4 plug behind the engine, I did and took 2 hours to fish it out with a wire loop, then dropped again, only took about 15 min the second time LOL! It also may be easier if you take the rubber insert out of the socket.

 

[wrestling coach]

A socket of this style may help to remove them.
http://www.summitracing.com/parts/kti-22527?seid=srese1&gclid=CKC2voiD48QCFUkkgQodIkYAjA

A length of rubber hose over the end of the spark plug can help guide and start your new plug going in. A little Anti-seeze on the threads of the new plug will help the next time you want to remove them.

Dennis

 

[stonyloam]

That is a nice tool, but I am not sure it would work on #4???

 

[wrestling coach]

Well my 470 is an '82 and it has been most useful getting some angle on my four plugs. But I don't find any of them too hard to get to other than a straight shot right down on the plug. The rubber hose makes the install a lot easier though.

Dennis

 

[Brock.Ward]

I recently did mine started by hand tightning it then getting the hex swivel in there and tightening it to specs, then I had just enough room to pull out the socket...

 

[stonyloam]

Well my 470 is an '82 and it has been most useful getting some angle on my four plugs. But I don't find any of them too hard to get to other than a straight shot right down on the plug. The rubber hose makes the install a lot easier though.

Dennis

Yeah I have an "87" so the reservoir is larger making things a little tighter in there.

 

[johnzonh]

had the same issue with mine...had to carefully feed a u-joint in there to get at them... a pain but it worked.

 

[H@ystack]

I ended up just putting a spark plug socket (rubber gasket removed) on the spark plug by hand. Then, as someone mentioned, just put a wrench on the end of it. Such a simple fix. Funny how one never thinks of such simple solutions unless you've ever seen it done before. I got the plugs in, wires done, new coils, and caps and it purrs like a cat......like a 30 year old cat, but still.

Thanks for the help! I know it wasn't necessarily a "boating" question, but more of a mechanical question.