Plug help, Johnson 115hp

[Al.]

Can anyone help with advice on spark plugs for a johnson 115hp

Details
Johnson v4 115hp
2 stroke.
Year 2006.

In it now are NGK BPR7HS-10 but I also found a site saying BPZ8HS-10

Thanks.

[paintman]

Have a play here: NGK Partfinder for Marine Spark / Glow Plugs

[Al.]

Hi Paintman.

I have been there, and it says bpz8hs-10

I will have to find out what the difference is between the two plugs.

[paintman]

NGK technical guide to plug part numbers here: http://www.ngksparkplugs.com/techinf...tnumberkey.pdf

Looks like the main difference is that the 8 is colder than the 7.
When the heat rating is too high:
The spark plug temperature remains too low and causes deposits to build up on the firing end; the deposits offer an electrical leakage path that gives rise to loss of sparks.

When the heat rating is too low:
The spark plug temperature rises too high and induces abnormal combustion (pre-ignition): this leads to melting of the spark plug electrodes as well as piston seizure and erosion.

ETA more here: http://www.ngk.de/en/technology-in-d...-the-ngk-code/

[dave3235]

Originally Posted by Al.

Can anyone help with advice on spark plugs for a johnson 115hp

Details
Johnson v4 115hp
2 stroke.
Year 2006.

In it now are NGK BPR7HS-10 but I also found a site saying BPZ8HS-10

Thanks.

Hi All

Why not phone a johnson service centre they would be able to tell you what should be in it.