NGK IZFR6J-11 question

[wildturkey]

This is for 175 proxs
SN 1B537766

was told the replacement plug is NGK IZFR6J without the 11 attached. Does anyone know this for a fact before I purchase the wrong plug? Thanks

[leonreno]

The -11 is just the indication for a Pre-Gapped plug to 1.1mm. The same plug without the -11 is just not spec’d to a specific gap.

[wildturkey]

The -11 is just the indication for a Pre-Gapped plug to 1.1mm. The same plug without the -11 is just not spec’d to a specific gap.

Thank you. Didn’t want to mess up.

[OldTimer57]

And in fact, you can NOT depend on the -11 plugs to be properly gapped. I have used both and found all were not very close. I buy mine from Rockauto for much less than a merc dealer. I gap 'em and run 'em with no problems of any kind.

[SilverFox579]

In the Mercury dealer's defense, the plugs they sell come with 1 year Mercury parts and labor warranty that only requires a receipt to enact should a plug fail and be determined to have caused other engine damage. For those who buy plugs elsewhere (myself included, source not revealed) you don't get the Mercury warranty. For some, that 1yr warranty on spark plugs is worth the additional cost of buying from a Mercury dealer.