Spark Plugs

**Glastron1987** · 02-28-2021, 01:31 PM

Using NGK BU8H (surface gap, non-resister, OEM) and BUZ8H (surface gap, resister) in all of my outboards (mostly V6's). They seem to last forever and never need adjustment.

Any advantage (or dis-advantage) expected in trying a gapped plug like B8HS or BPZ8HS-10?

...or is there an iridium equivalent that could be tried as well? I see there is a Denso IWF24 that matches physically, but not sure what to think of the heat range.

**Glastron1987** · 02-28-2021, 01:59 PM

Looks like NGK BR8HIX is the iridium matchup.

**mach351** · 02-28-2021, 05:56 PM

I use Br8hs-10’s because they run good, are easy to read, and cheap.

**laser_ED** · 02-28-2021, 08:13 PM

Originally Posted by Glastron1987

Looks like NGK BR8HIX is the iridium matchup.

Do not spend the money for the iridium,The plugs that mach 351 posted,ngk br8hs 10s are the best in a carb or EFI 2.5 200.We have used these plugs in everday motors or full on race motors....P,S..I use the BR8HIX iridium in my V6 pro drag engine??????

**Glastron1987** · 02-28-2021, 08:59 PM

Thanks. BR8HS-10's do look like an economical choice and they are resistor as well. Maybe I'll given them a try.

**Glastron1987** · 06-02-2023, 07:59 PM

So I tried the BR8SH-10 in place of the BUZ8H's I have been using for years in my XR4. They seemed to run fine except at low speed they rean rougher. I suspect they only needed to be run a little leaner at low speed. So, I was planning to make a minor low speed adjustment, but then remember that my particular carbs have jets even for low speed. So, I went back to the BUZ8H's, I don't want to mess with the jets. At least I gave it a try.

**Chaz** · 06-02-2023, 09:27 PM

The -10 means that they come gapped @ 1.0 mm. Which is .03937 .. just call it .040

There is no reason to run that wide of a gap ... especially with a low output ignition.

Try closing them down to .025 - .030 .. it will quit shootin ducks down low ..