320 sparkplugs

[Harmon]

About to dive in to Twin 5.7 tuneup. Any words of advice/tips tricks shortcuts/workarounds on accessing the plugs? Im guessing its a blind process. Do you use dielectric grease on all plug boots?
How about removing anything to facilitate the process?

 

[Brite Idea]

Yes to dielectric grease but also consider plug wires with the usual stuff.

 

[Bt Doctur]

depending on your manifolds you may need to grind down the "hex" portion of the socket

 

[Harmon]

depending on your manifolds you may need to grind down the "hex" portion of the socket

Thanks, an added step in the boat yard, what fun

 

[Bt Doctur]

If you dont grind it down all you will do is break the new spark plugs
click to enlarge

 

[JimG]

I didn't have to do that... But if you have Horizons you will have to take a hose lose and spill anti-freeze to get to one of them.

 

[Mknupp]

A small length of rubber vacuum hose on the end of spark plug will help you get it started into the cylinder head, saves a lot of bilge diving for dropped plugs.

 

[Maggieiscrazy]

Changed my plugs last year at 760 hours. They had black paint on them from manufacture. I assume they were original to the boat.

 

[Harmon]

I didn't have to do that... But if you have Horizons you will have to take a hose lose and spill anti-freeze to get to one of them.

I do have Horizons as a matter of fact. It must be a hose off a manifold I'm guessing?

 

[JimG]

I do have Horizons as a matter of fact. It must be a hose off a manifold I'm guessing?

Yes hose off of the manifold... starboard motor in the center as I recall.

 

[Harmon]

Yes hose off of the manifold... starboard motor in the center as I recall.

Much obliged

 

[Harmon]

Finished 16 plugs yesterday, one hose off bottom port engine/outboard. Dumped the magic antifreeze so I'll have to topoff. All plugs looked good except one was suspect. Looked cleaner and drier than others and also had some scaling on the rim of the plug. hoping just layup moisture and I'm going to check after fire up and run for a while.

 

[Harmon]

On another note, what is the best resource for exhaust hoses. 2.5 ID smooth and a 2" ID corrugated wet type. 6 foot