Changing Spark Plug for Dummies

[jstutz101]

I just got done changing my spark plugs on a 5.0L Mercruiser. If you have never changed them before (like myself) it's not a lot of fun. The bad part is the boat is running great but the plugs haven't been changed in 18 years!

After trying to use a regular spark plug socket that won't fit, I bought one of these from autozone.

http://www.autozone.com/autozone/ca...Handle+Spark+Plug+Socket&brandName=Great+Neck

Its a cheap tool but it works. I am not sure what else it would good for but it works good for changing Mercruiser plugs. The spark plugs didn't come out easy so I also added a little torque using a pair of channel locks.

Another lesson learned is NAPA can order these plugs ($2.10) if they don't have them in stock. I ended up buying them at a Marine Shop for $4.25 a piece. I had the day off from work and free time is hard to come by.

Hopefully that helps somebody...

 

[Gary H NC]

Re: Changing Spark Plug for Dummies

Hope you never have do change them on a OMC 351....worst ever.

The Merc plugs are not that bad after you do it a couple times..
Don S has a diagram where you can taper a socket down on a bench grinder.
Taper it just so there is enough metal left for ratchet or extension will still go in.
I made one and it works great.
I do have one of those T handle sockets too...

 

[jstutz101]

Re: Changing Spark Plug for Dummies

Hope you never have do change them on a OMC 351....worst ever.

The Merc plugs are not that bad after you do it a couple times..
Don S has a diagram where you can taper a socket down on a bench grinder.
Taper it just so there is enough metal left for ratchet or extension will still go in.
I made one and it works great.
I do have one of those T handle sockets too...

I was going to grind down the socket but it was easier just to buy a "thinner" one. Seems silly that a standard spark plug socket dosent fit. Engineering mistake I guess.

 

[Bifflefan]

Re: Changing Spark Plug for Dummies

an easy way to get them back in with out cros threading is to take a piece or 3/8 vacum line, 8" or so, jam it on the plug then you can use it to twist the plug in. It will self center the plug and wont let you turn it if the threads arent right.

 

[jakebrake]

Re: Changing Spark Plug for Dummies

what else? the word "camaro" comes to mind. come to think of it, that was a 5.0 too.