Spark Plugs - Washer

rjbathgate · 16 September 2009, 01:20

Hey,

I'm replacing the spark plugs in my Mercury 60HP 2 Stroke.

I'm replacing like for like/the recommended plug:

NGK BPZ8H-N-10

However, the plugs in the outboard which I'm replacing DO NOT have washers.

The new one's i've just purchases DO have washers.

Do I simply use the washer ones, but adjust the amount of turn after finger tight (1/16 no washer, 1/4 with washer).

Or do I need to take the plugs back and get non washer versions?

Cheers in advance
Rob

uncle al · 16 September 2009, 07:18

just take them out of the package make sure the gap is correct (1mm or 40thou) put them into your powerhead and torque to 20lbs/ft

jyasaki · 17 September 2009, 03:47

The washers are soft copper or aluminum, designed to crush and seal the plug into the head. You *do* need them.

Assuming you've got the correct plugs for the motor, not having the washers may allow the plug to extend too deep in the chamber, and in the worst case may hit the cylinder as it comes up.

jky

captnjack · 17 September 2009, 17:21

Double check the old plugs didn't actually have washers that are stuck down in the hole. The plug would be at the wrong height if you accidentally used the old plus a new washer.