Outboard spark plug gap

[Rabbitman09]

I have a 2003 mercury 75 elpto 2-stroke on one of my boats. I changed the spark plugs and it isn’t running right. The old spark plugs were all the same....NGK BUZHW-2. A buddy of mine asked me if I tapped them and I did not because these are gappless. They don’t have the wire you can bend. Does anyone know if some outboards take the same size and gap spark plugs? If they need to be gapped. I don’t know how to check for gap on this type of plug. Any help would be appreciated. This a 3-cylinder 75hp.

[rp]

Looks like you have the wrong plugs. A quick look at Mercury plugs shows gaps on that year of 1mm for 2 stroke, .7 for 4 stroke.

[Rabbitman09]

I’m showing I have the right plugs. Are all three cyclindar plugs gapped the same?

[ecu1984]

I could be wrong but if its a gapless plug without the electrode thingy, then you just screw em in.
Are they just like the old plugs you took out?
Did you get a plug wire crossed or pull the crimp metal end off one of the wires inside the boot when tugging on it?

[ecu1984]

I’m showing I have the right plugs. Are all three cyclindar plugs gapped the same?

yes, the gap doesn't change between cylinders

[Rabbitman09]

yes, the gap doesn't change between cylinders

Thanks for the information. The boat was sitting for a while and I did a bunch of PM stuff to it before taking it out. I think it’s a fuel issue. It ran fine the other day testing it out. Changing the sparks plugs was the only thing I did between trips. I’m gonna clean the carburetors and see if that doesn’t fix it.

[ecu1984]

you can check and see if the plugs are firing ok
with it idling, pull a plug wire off......if it stumbles or knocks off......that plug was getting fire.
Then repeat with the next plug, and so on.....one at a time and put the wire back on after each one.
If you pull the wire off a plug and nothing changes with the motor, then that cylinder has a firing issue.