I am looking for stocking up on spare spark plugs. But I get confused
as of which spark plug to use.

The spark plugs in the motor all have this marking:
BPZ8H-N 10 (note the 'Z')

The spark plug that SELOC Outboard Repair Manual (for my motor)
suggests using this spark plug:
BP8H-N 10 (note no 'Z')

Two local marine supply stores (West Marine, Boater World) only carry
this spark plug:
BP8H-N 10 (note no 'Z')

According to Spark Plug Application Guide, "BP8H-N 10" is for older
motor 1990-2000 (my motor) and "BPZ8H-N 10" is for newer motors
2001-200?. Seem like I should be using the older version to match my
old motor. But: If I start using an older version of the spark plug to
replace an existing spark plugs when it fails, I will be mixing old
with new spark plugs. Is this OK to mix old version with new?

Should I replace all the spark plugs with old version all at once?

Should I stick with the tried-and-true / new version of spark plugs
that are already in my motor? Where can I find this new version of
spark plugs anyway? Please note that I cannot find it in local store.

Please help. Thanks.

Jay Chan

wrote:
I am looking for stocking up on spare spark plugs. But I get confused
as of which spark plug to use.

The spark plugs in the motor all have this marking:
BPZ8H-N 10 (note the 'Z')

The spark plug that SELOC Outboard Repair Manual (for my motor)
suggests using this spark plug:
BP8H-N 10 (note no 'Z')

Two local marine supply stores (West Marine, Boater World) only carry
this spark plug:
BP8H-N 10 (note no 'Z')

According to Spark Plug Application Guide, "BP8H-N 10" is for older
motor 1990-2000 (my motor) and "BPZ8H-N 10" is for newer motors
2001-200?. Seem like I should be using the older version to match my
old motor. But: If I start using an older version of the spark plug to
replace an existing spark plugs when it fails, I will be mixing old
with new spark plugs. Is this OK to mix old version with new?

Should I replace all the spark plugs with old version all at once?

Should I stick with the tried-and-true / new version of spark plugs
that are already in my motor? Where can I find this new version of
spark plugs anyway? Please note that I cannot find it in local store.

Please help. Thanks.

Jay Chan


I usually play it safe and go with the plugs recommended in the
manual...or any replacements recommended by the dealer. Who knows...the
PO of your boat may have picked up the current plugs by mistake.
Yes, I would replace both/all plugs at once. Start fresh for next spring.

BPZ8H-N

The Z means it is a radio suppression plug. If you are not getting a
buzz in your radio, don't worry about it.

Thanks for the info. This makes sense. I will not worry about this
and start stocking up with spare spark plugs with BP8H-N-10 marking.
That version is easily available in local stores and is quite cheap.

I will add a VHF radio into the boat, and I will see how it goes.

Jay Chan

I usually play it safe and go with the plugs recommended in the
manual...or any replacements recommended by the dealer. Who knows...the
PO of your boat may have picked up the current plugs by mistake.
Yes, I would replace both/all plugs at once. Start fresh for next spring.

This was exactly what the salesman in a marine supply store suggested.

But if the new version only affects the radio frequency and doesn't
affect anything in the motor. I will just leave it alone. Anyway, I
will see how it goes when I add a VHF radio to the boat. At that time
I will tell the difference before/after adding the old version if spark
plug into the motor.

Jay Chan