I have a 2021 Mercury Pro XS 200 (V8) with serial number 3B103421.

The engine has 35.4 hours. I have a Vessel View Mobile installed.

Engine started running rough. I have a 2022 Tracker V18 Combo that I use for fishing.

I have read elsewhere in this forum that it seems if there is a lot of low RPM time that spark plugs could need changing well before the 100 hour mark. I get where I am going on a small lake (Hillsdale Lake in Kansas mostly and others of similar size) and spend most of the time trolling on the electric Minn Kota.

Engine started rattling a bit and didn't sound quite right but not getting any codes. I use Quick care fuel treatment from Walmart. Usually use regular gas from high volume stations.

I know it says 15 foot pounds for salt water (which I don't go in). I don't have a torque wrench on my ratchet.

How tight (how many turns after hand tight) would I turn after ensuring the gap is correct? Hopefully this resolves the issue. All help is appreciated.

Thank you -Will