Outboard Sparkplug question

[captpierre]

Winterized my 2007 Yammy 115.

Had put new plugs in this past spring.

I don't have a torque wrench so I just snug them by feel. Every fall after fogging.

In the past it always took a bit of effort to loosen them. As you would expect.

This year it took almost no effort at all with the new NKG plugs.

Also the very end of the plugs were clean.

But the shoulders of all 4 plugs had black carbon on them.

Do I have a problem?

Engine starts/runs perfectly

Thanks

Peter.

[2 tone z71]

Sounds like it's burning fine to me ..my yammy trolls a lot the plugs get black ,sooty,wet ,I wouldn't be concerned

[chris.brock]

2 or 4 stroke? pretty sure it's a 4

 

what part is the shoulder? middle of the plug? terminal is where the cap goes on, electrode is the part that sparks

 

 

Sounds like you didn't give them quite enough torque this spring, blow by

Edited November 1, 2015 by chris.brock

[NANUK]

Sounds like its burning fine,

Spark plugs have crush washers and should be tightened properly, if you can't do it by the "feel" its a good idea to invest in a torque wrench, keeps the guess work out and always handy to have one around.

[captpierre]

Thanks guys.

Maybe I need to snug them next spring after a month of use.

I'll keep an eye out for a torque wrench when they go on sale at CT.

[leaf4]

If you have a princess auto close to you, they have a couple different ones on sale at the moment

[irishfield]

They are this week @ 1/2 price for the mastercraft brand. $47.99 for the 3/8 drive and $49.99 for 1/2". Buy them both for the price of one and you can do your own tires as well. I have them both and they're a nice "click" when you hit the setting. Also a ratchet head as a bonus.

[DanD]

A proper torque on a spark plug can be critical on most engines. Too loose and blow-by will cover the treads; this carbon build up could start to electrically insulate the spark plug from the cylinder head and cause misfiring. Also a loose spark plug could cause it to blow out; it's not just compression pressures it has to withstand; but combustion pressures that can blow out a plug; usually taking the treads in the head with it.

As Wayne said get both wrenches; there's no such wrench that will accurately torque everything.

A click type torque wrench is its most accurate, when the setting you are using is above 1/4 of it minimum setting and 1/4 below its maximum setting. So if you plan on torquing spark plugs and possibly vehicle wheels you'll need both. Not sure what the torque would be on your Yammy's spark plugs; but most automotive spark plugs going into an aluminum cylinder head are between 10-15 Ft. Lbs. Wheels are 90-120 Ft. Lbs on light duty vehicles.

 

Dan.