Re: 1997 Johnson 175 Fast Strike
All V-6 60 degree (looper) carb engines use the same plug. The only other plugs listed are for 90 degree (crossflow) engines. The Faststrike/Intruder models are good engines
From 2008 BRP sparkpug chart
150, 175 (60? V6) 1991 & newer QL78YC .030
150 Commercial (60? V6) 1993 - 2001 QL78YC .030
150, 155 (90? crossflow V6) 1978 - 1987 UL77V or L16V Surface Gap
150, 175 (90? crossflow V6) 1988 - 1991 QL77JC4 .030