Spark plugs M9.9B2

[flangler]

Which plugs should be used for this motor? The ones I pulled from the motor are BP7HS-10(0.040). On iboats website they state it should be running B7HS-10(0.032). The difference is the gap. Under the cowling it says to use B7HS-10 gaped at 0.040. I'm a bit confused. Any help is appreciated.

 

[Sea Rider]

Re: Spark plugs M9.9B2

You could use BR7HS-10, B7HS-10 or B7HS, this model must be regapped to 1.0 mm as comes factory gapped to just 0.7 mm. The R stands for "resistor inside" and 10 ending for "1.0 mm" factory gapped. For peace of mind read Made in Japan as there are same plugs made who knows where ?

Happy Boating

 

[flangler]

Re: Spark plugs M9.9B2

So if I use the B7HS-10 I wouldn't need to gap it right? Because it's already gaped correctly.

 

[Sea Rider]

Re: Spark plugs M9.9B2

So if I use the B7HS-10 I wouldn't need to gap it right? Because it's already gaped correctly.

Removed BP7HS-10 has noting to do with BR7HS-10, first protrudes electrode deeper into head compared to second. Correct, having a 10 ending means it's already factory gapped to 1.0. Anyway, must always check gap with gauge, just in case.

Happy Boating