Best plugs for 1990 Mariner

[tannedman]

Hello i just picked up a fisher bass boat with a 100 hp 2x2 mariner runs great at low speed but when you open it up has some issue's . I pulled the plugs top 2 look fine bottom 2 black but the plugs in it don't have the nipple;s what plugs would be considered the best for this type of motor Thanks

 

[Silvertip]

Re: Best plugs for 1990 Mariner

The best pougs are ones listed on the tune up decal on the side of the motor.

 

[carholme]

Re: Best plugs for 1990 Mariner

Parts listing for your engine:

http://www.crowleymarine.com/mercury-outboard/359.cfm

See item 10 under Electrical Components

The reason your plugs do not have nipples is that they are surface gap type.


Gerry

 

[CharlieB]

Re: Best plugs for 1990 Mariner

Surface gap plugs work best in engines that see mostly higher RPM useage.

Many of the 2 + 2 series have been spec'd with the extended tip electrode plugs that most people recognize as a more 'normal' spark plug.

Depending on how hard you operate your motor, a change in style can be benificial, but my 2 + 2 runs best with the factory recommended NGK BPZ8 HS gapped at .032 to .035 or the cheaper BPR8HS, which are cheap enough that I change them every spring after initial fire up to burn off that years fogging oil.

 

[tannedman]

Re: Best plugs for 1990 Mariner

Thanks guys all types are differet then what i was able to find BINGING them NGK BP8H-N-10 is what i found