Mercury 2stroke plugs surface gap vs standard?

[Aviator04]

Hey, does anyone know if there would be clearance issues running a standard electrode plug in a 90hp elpto? I’ve had a few people swear that these 2strokes will idle & run better, especially at lower speeds over a surface gap plug. Is anyone here running standard type plugs?

 

[Chris1956]

Do you happen to have a stock number for a conventional spark plug for your motor? If not, which one are you planning to run.

 

[Aviator04]

Chris, I’m currently running NGK buhw-2 plugs. Any chance you know of a similar heat plug that’s non surface gap? Someone with a 115 merc recommended ngk bp8h-N-10, but not the exact same motor..I did just pick up a set of them and after measuring it appears I have plenty of clearance. I just don’t want to run something too hot and burn up a piston.

 

[jimmbo]

I ran the Factory plugs, which were the Surface Gap type, for 14 yrs in my 84 115, never had any fouling or problems with them.

The Surface gap plugs are Very Cold,
FWIW, the Factory Plugs were NGKs, which ones? I traded that motor off 18 yrs ago

 

[achris]

If the spec is surface plugs, don't use anything but surface plugs.

 

[Texasmark]

Hey, does anyone know if there would be clearance issues running a standard electrode plug in a 90hp elpto? I’ve had a few people swear that these 2strokes will idle & run better, especially at lower speeds over a surface gap plug. Is anyone here running standard type plugs?

My service manual listed both types for that engine....I no longer have the boat nor the manual so I don't have the numbers. My take on which plug to use is that the SG doesn't get hot like conventional plugs (might) when running at WOT for long periods. The conventional plugs are said to foul less when doing a lot of trolling, or general types of running.

 

[Aviator04]

My service manual listed both types for that engine....I no longer have the boat nor the manual so I don't have the numbers. My take on which plug to use is that the SG doesn't get hot like conventional plugs (might) when running at WOT for long periods. The conventional plugs are said to foul less when doing a lot of trolling, or general types of running.

.

do you remember what year your motor was? I can’t find any other plug alternatives on mine.. I’ve been trying eliminate this low speed shake/vibration I have for a good month now. I’ve replaced a lot of parts and tried adjusting the carb settings many times to no avail. I’m hoping a standard type plug might help since they’re supposed to perform better at low speeds

 

[achris]

Try running a higher octane fuel. The slower burn rate will help.

BTW, what is your engine serial number? I'll look up my manuals and see what plugs you should be running.

Chris.

 

[Aviator04]

Try running a higher octane fuel. The slower burn rate will help.

BTW, what is your engine serial number? I'll look up my manuals and see what plugs you should be running.

Chris.

My serial # 1b357796...it’s a 2006 90 elpto. Will try running high octane. Thank you!