Wrong spark plug

[steven9586]

Hi Guys

I've just bought a second hand 15hp 2 stroke mercury 2004 model and when checking the spark plugs it has the wrong ones in. The manual states using BPZ8HS-15 but it had BP8HS-10 fitted.

Will this have caused any detrimental effects to the outboard and why would someone do this?

I have ordered the correct ones but just need a little bit advice on this matter.

Also could I use these as spares as I've seen the engine running with them fitted and it seemed fine.

Cheers

Steven

[kubcat]

The "Z" means it is an inductive resistor plug and the end number is the gap it was gapped to when manufactured.

All else is the same.

As one should always check the spark plug gap before fitting, there is no need to be overly concerned about the last number so the only real difference is that one is an inductive resistor plug and the other isn't.

Inductive resistor plugs are less likely to cause interference to electronics on board and to late model outboard CDI ignitions.

The short answer is if they are working fine, use them, but make sure they are gapped correctly.