Plug Info

[Sea Rider]

Hi all,

A friend of mine has a Mercury 225 HP Offshore model outboard, it's a six carbed engine, needs plugs, Was wondering if anyone knows which are the right plugs in NGK and Champion brands and their correct gap.
Thanks in advance.

Happy Boating

 

[Barnacle_Bill]

Re: Plug Info

You can look that up on their websites.

 

[oldman570]

Re: Plug Info

NGK BU8H
Surface Gap for 225 Hp except pro max and magnum
NGK BUZHW
Surface Gap for 225 pro max and magnum
I belive these are what is called for in your motor.
Oldman570

 

[N3UP]

Re: Plug Info

What year is the motor?

My 1996 Mariner (Merc) specs NGK, but newer years spec a Champion plug.

 

[Sea Rider]

Re: Plug Info

What year is the motor?

My 1996 Mariner (Merc) specs NGK, but newer years spec a Champion plug.

Hard to tell, is there a plate, sticker whatever to look for, It's old, will post a pic latter.

Happy Boating

 

[Sea Rider]

Re: Plug Info

Here are some pics of the engine, accordingly to CD Mercury Parts looked under :

225 (3.0 Lt) carbed states : Champion QL 77JC4 or NGKBPZ8H-N-10
225 Seapro (3.0 Lt) carbed states : Same as above
The model list does not specify a Offshore model.

Is it acceptable to use one any of both mentioned plugs ? Will both perform same ?
The actual plugs are NGK BR8HS-10 as both previous mentioned plugs are extremely difficult to find/not available down here. Could wrong plugs lead an engine to perform bad on all throttle range after passing idle ? The engine has received a total overhaul recondition.

Happy Boating

 

[oldman570]

Re: Plug Info

Running plugs that are not recommed by the manufacture could have a effect on the motor at high RPM's as theycould be of a diffrent heat range and start to foul or blow out . There are some motors that require that the plugs be instauled in just a certian way on some motors and that could be the case on your motor, but not sure. Try going to 1manual.com on the net and it has info on all newer Merc's . You will need Adobie reader and will have to let it download and go from there for your motor.
Oldman570