A friend of mine has twin 496HO’s in his boat. He was unable to access the rear spark plugs (I believe #7) on the port side because there is an oil line directly in front of the spark plug boot. Can anybody offer a trick to getting this plug changed?
Thanks in advance!

Yea, the trick is a pair of 502's , will fix the problem.....just kidding , I have heard that they were hard to replace & exspensive too. Gotta love it.

Hope everything is doing well for you all. See you all sooooooon!!!!!!!

I just went through this last week, same thing port engine #7. I had disconnect the wire at the coil, let it hang down loose, then rotate the boot on the plug so it pointed upward and over the oil line, instead of under it. It was a pain, but I got it off.

You could also try loosening the oil line connection at the cooler (just below the #7 plug) and rotating it out of the way a little.

Dave

The platinum tipped plugs in a 496 Merc should not need changing, cleaning or regapping in less than 250 to 300 HRS use. Unless you have a miss or a problem, leave them alone!
Ray @ Raylar

they said that about my triton ford motor 100k no tune up,i have had to change them twice,but these are easier to check in the boat.

I believe these motors had 300+ hours on them.

getting them out will be easier than putting them back...
disconnect what you need to...for removal, then when replacing.....put the new plug into a short length of rubber hose....use it like a rubber socket to get the plug started...its an old 409 ford trick, for cramped places..i have the same problem with my sutphen, i use the hose on all the plugs...cuts the time in half...
hope it helps..
c

Omg, I know this is an ancient thread, but I have to say the rubber hose trick on inserting port plug #7 just saved me from lighting my boat on fire!