Tohatsu NGK Spark Plugs

[Sea Rider]

Most 2 strokes Tohatsu portables to medium range engines uses NGK BR7HS-10 plugs, what happens if due to a shortage of them, NGK BR8HS-10 are used. Although both termic range are next to each other, 8 is a bit colder than 7. Being colder will rest 50?-100? from ideal engine temp achieved with 7.

Besides fouling faster that 7 at long idle periods, what could happen to the engine in the long run ? Will the engine still perform fine ?

Happy Boating

 

[pvanv]

Re: Tohatsu NGK Spark Plugs

Too cold=fouling and carbon build-up.

 

[Sea Rider]

Re: Tohatsu NGK Spark Plugs

Paul,

That's why I thought, will exterior boating temp wether hot, medium hot, cold affect carbon build up in less or more proportion, or has nothing to do, it's the less engine temp achieved that builds carbon inside combustion chambers.

Do you guys use NGK BR7HS or B7HS plugs ? Asking this because while same with 10 ending are made in Japan, the ones mentioned have no indication where they are made, probably in Brasil, China wherever. Although very cheap seems not to last that long as originals. Comes factory gapped to 0.7 mm, must be regapped to 1.0 mm if wanting engine to perform well.

Happy Boating

 

[pvanv]

Re: Tohatsu NGK Spark Plugs

Ambient temps only affect how long it tales to warm up. We use mostly non-R, unless the motor is Canadian, then we must use R plugs for RFI. Everything we buy these days is -10.

 

[Sea Rider]

Re: Tohatsu NGK Spark Plugs

Paul,

Wrote Tohatsu USA tech dept inquiring about plugs compatibility. The tech rep that answered said when inquired about using Champion L82C. That's the brand and type recommended in owner's maual as alternative to NGK, but must be gapped to 1.0 mm as they come factory gapped to just 0.8 mm

He said that Jap NGK plugs performs much better. In case both mentioned plugs are unavailable recommended using NGK BP-7HS gapped to 0.8 mm. If 2 strokes engines normally uses1.0 mm gapped plugs up to medium HP engines why would he recommend to gap them around 0.8 mm ?

What's the advantage or disadvantage of using protruding tip plugs with respect to standard ones bearing same (7) heat range code ? Will you achieve good engine performance when gapped to 1.0 mm ?

Happy Boating

 

[pvanv]

Re: Tohatsu NGK Spark Plugs

You ALWAYS check the gap. Always use manufacturer's gap specifications.

Projected tip is used on some motors. In others, the tip could contact the piston. Not good. If wanting Projected tip, and not available, the standard tip will work OK, but may not stay as clean for as long.

 

[Sea Rider]

Re: Tohatsu NGK Spark Plugs

Thanks Paul,

But the inquiry was about using BP7HS on Tohatsu 18/30 2 strokes engines, have still 2 complete full boxes of them and was wondering it it was possible to use them without damaging the piston being protruded tips. If you haven't used them in these specific engines, what would you suggest ? Try them and see what happens, post results ?

Which brand would you preffer NGK B7HS-10 standard plugs or Champion L82C-10 100% compatible plugs ?

Happy Boating

 

[pvanv]

Re: Tohatsu NGK Spark Plugs

NGK for Tohatsu motors. The P tip should be OK.