Secrets to removing #4 spark plug

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FiatJim
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Your car is a: 1973 spider refurbished
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Secrets to removing #4 spark plug

Post by FiatJim »

My 1973 124 Spider just refuses to let go of the spark plug closest to the fire wall. The spark plug was installed by a pro mechanic and he really tightened it down!

I have tried using ratchet with a short extension, a "wobble" in between the spark plug socket and ratchet and a "special" spark plug socket with built in ratchet. But I haven't gotten it to loosen at all.

I read about the horrors of breaking the plug, or stripping the threads and gotten very cautious. What the heck is the secret to getting the thing out?

Jim
18Fiatsandcounting
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Your car is a: 1969 and 1971 124 spiders
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Re: Secrets to removing #4 spark plug

Post by 18Fiatsandcounting »

For some reason, people overtighten the spark plugs, even "pro" mechanics. They don't need to be THAT tight....

But my diatribe isn't helping your situation. If you can get a socket on the plug (which it sounds like you can), then you can use a very short extension with a ratchet drive in between the two camboxes. Makes it hard to get much of a turn for each click, but you might be able to break it free.

Normally for the #4 plug, I use a 3/8" drive socket, then a universal joint (high quality "impact grade"), then a six inch extension, then the ratchet drive. But I don't overtighten my plugs. You could also use a 1/2" spark plug socket, and 1/2" versions of the above, to get more torque on the socket.

You really don't want to shear off the plug as that means the cylinder head has to come off. D'oh.... To be honest, it might be worth taking it to a good mechanic who likely has all the variations of tools to get that plug out.

-Bryan
FiatJim
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Your car is a: 1973 spider refurbished
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Re: Secrets to removing #4 spark plug

Post by FiatJim »

Thanks Bryan, I appreciate your insights.

I picked up am open end wrench which fits the outside of the spark plug socket. I hope I can get enough torque to safely loosen the plug. I plan on using some wood on each side of the socket to stabilize when the force gets applied - I hope that this will decrease the chances of me busting the spark plug.

The other 3 had A LOT of carbon build up; so that plug really needs to get changed out. Then I need to learn how to lean the mixture a little. One "challenge at a time".

Jim
18Fiatsandcounting
Posts: 3798
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Your car is a: 1969 and 1971 124 spiders
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Re: Secrets to removing #4 spark plug

Post by 18Fiatsandcounting »

Regarding the rich mixture, do you know what carburetor you have? And backing up a step, what engine you have? If original, a 1973 is likely to be a 1592cc engine with a 28/36 DHSA3 carb or possibly a late 1608 engine with a 28/36 DHSA2 carb. The carbs are for the most part identical.

The easiest way to tell which engine you have is to see whether you have an external thermostat (that thing with 3 hoses rearwards of the radiator). A 1608 engine would have the external thermostat, while the 1592 would have an internal thermostat under the coolant neck at the front of the cylinder head. A 1592 would also have the dual points ignition system, but as this is often problematic, it's very common to see the distributor converted back to a single point system.

As for the carbon build up on the plugs, it could be a problem with the carb causing it to run rich, you could have the wrong plugs, the engine may be running too cool, or you are only doing short trips.

-Bryan
FiatJim
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Your car is a: 1973 spider refurbished
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Re: Secrets to removing #4 spark plug

Post by FiatJim »

I an sorry for the long delay in responding; I did not mean to ghost you.
I had a surgery and the recovery has just taken the wind out of my sails.

The spark plugs are all set! After getting myself healed up, the next project will be the carb/fuel mixture


Thanks for the help & education

Jim
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