SX190 Spark Plugs

[TimeOnTheWater07]

Hey all. Went to change my spark plugs for the first time and wanted opinions as to whether or not they need it. I have a new set and my intention was to keep the originals for use when winterizing/start of season.

Unfortunately I have no service records to see if they’ve been changed before, as the previous owner didn’t care to keep any. The boat seems to be performing pretty well, 2021 SX190 - 1.8L

We have had the boat out twice so far this year to ensure that, if it was fogged, the oil is burned off. The boat never smoked at all like my VX waverunner did last year, so I’m not sure Wonderland even fogged my engine when winterized.
Do these spark plugs look fouled or like they need to be replaced? The others looked similar.

 

[HawaiiBreeze]

They look lean burning. Your insulator is basically white. Yamaha's 1.8 engines are lean burning so this appears to be Normal given just two outings.

 

[212s]

Hey all. Went to change my spark plugs for the first time and wanted opinions as to whether or not they need it.

How many hours? You should be able to get 300+ hours out of a new set and those look fine.
Also check the gap on them, they should be within 0.8 - 0.9mm.
Here's a page to see what different plug conditions look like:

https://ngksparkplugs.com/en/resources/read-spark-plug

Our plugs should be a little lighter grey than the first "normal" plug colour.

By the way, You don't need to change your plugs until they're worn otherwise you're just throwing away perfectly good plugs. If everything is good, engine idles smooth, runs well, good colour, etc., then just pull them to inspect their condition once a year or every 100 hours. If you notice a loss in performance before the 100 hours, pull them and inspect. If they're worn (gap over 0.9mm) or dirty, wet, etc., change them out and test the boat again, then pull the plugs to see their condition and compare to the spark plug colour pics. Otherwise run them and enjoy!

 

[TimeOnTheWater07]

Thanks for the feedback and link to more info.

57 hours on the boat now, and I bought it last August with 50 hours on it. These may be the plugs from the factory.
Everyone says winterizing/fogging fouls the plugs, so either my boat didn’t get fogged at the dealer I took it to or I’m not sure I know what a fouled plug looks like.

I plan to keep using them for now and I’ll save the new ones I bought.

 

[212s]

Everyone says winterizing/fogging fouls the plugs, so either my boat didn’t get fogged at the dealer I took it to or I’m not sure I know what a fouled plug looks like.

It looks dark and wet (see the pics on that site). If it was lightly fogged, and the engines fired up in the spring, they would quickly burn off the fogging oil and look normal after a good run to heat them up.

I've never fogged for winter storage and never had an issue with the plugs. If I was storing long term for something like a year, I would fog manually into the cylinder with the plugs pulled. But aside from that, I don't think fogging is really necessary for winter storage.