spark plugs

[JJB61Jon]

1989 Yamaha 175 2 stroke, sticker in motor says B8HS 10 and online charts say BR8HS 10. Should I go with the resistor plug ?

 

[99yam40]

back in the good old days I think they put resister plugs on cars motors to help reduce the radio noise
I am not sure why they went to R plugs on boat motors

 

[Sea Rider]

BR spark plugs are excellent if will be using electronic toys on board, if not the B8HS-10 will work OK gaped tight to 1.0 mm...

Happy Boating​

 

[JJB61Jon]

I'm green coming into outboards, I'm awaiting my Yamaha service manual.The charts online for plugs are different. I saw gaps on charts from .43 and also .04. You mentioned gap to 1mm, is that the same as .04 ? The plugs in the motor are gapped at .30 to.40, so this would be incorrect. Could the wrong gap(excessive) cause a rough idle but run like a champ 1/2 to full throttle ?

 

[Faztbullet]

Before super dooper fishfinders and GPS units it was fine to run non resistors. If you have not been having any interference problems use the non resistor plugs. 0.04 =1MM=.039 so plugs are gapped correctly.

 

[JJB61Jon]

Thank you

 

[Sea Rider]

I'm green coming into outboards, I'm awaiting my Yamaha service manual.The charts online for plugs are different. I saw gaps on charts from .43 and also .04. You mentioned gap to 1mm, is that the same as .04 ? The plugs in the motor are gapped at .30 to.40, so this would be incorrect. Could the wrong gap(excessive) cause a rough idle but run like a champ 1/2 to full throttle ?

If Yam calls for NGK B8HS-10 those recommended spark plugs must be used. The side 10 stands for 1.0 mm factory gapped, if without an ending number are usually gapped to much less say 0.7mm...

Happy Boating​