2004 Merc 9.9 spark plugs

[lakelover]

I was looking over my new-to-me program 9.9 Merc outboard (ser # 0T 910996) and noticed that it came equipped with different plugs than the manual calls for. The manual calls for NGK BP8HS-15, but it is equipped with BP8H-N10.<br /><br />What's the difference between these two plugs and will it make a difference in performance? I've started it in a barrel but haven't had it out on the boat yet.<br /><br />Also does anyone have a link for checking out mfg. dates by serial numbers?<br /><br />Thanks.

 

[JB]

Re: 2004 Merc 9.9 spark plugs

Merc Troubles and Repair topic.