Following the advice from some recent posts, I changed the port temp sensor in my 2000 Challenger (240 Merc) when I did my spring tune up. Gave the marina my Ser. number (OE 383201) and they said my boat took part # 13536A14. I changed both fuel filters, all 6 spark plugs, and the temp sensor (which didn't fit flush like the old one, it stuck out a little bit further), and yes I used heat sink compound.
After 20 min. on the water I had fouled all 3 plugs on the starboard side but the port side plugs looked fine. I put in 3 new plugs and off we went. After 15 min. I had fouled 2 plugs in the starboard side and 1 on the port side. I put the old sensor back in, changed all 6 plugs (the local NAPA charges $6.59ea. for BPZ8HS plugs, does that seem high to anyone but me?) and the boat ran fine the rest of the weekend. Although it does seem to smoke a lot more than it did before and it seems to use more fuel. Last year I could pull a 3-person tube for 5-6 hours before my low fuel buzzer went off. This weekend it was going off after 4 to 4.5 hours. I run premium fuel and a bottle of Seafoam in every other tank full.
After 20 min. on the water I had fouled all 3 plugs on the starboard side but the port side plugs looked fine. I put in 3 new plugs and off we went. After 15 min. I had fouled 2 plugs in the starboard side and 1 on the port side. I put the old sensor back in, changed all 6 plugs (the local NAPA charges $6.59ea. for BPZ8HS plugs, does that seem high to anyone but me?) and the boat ran fine the rest of the weekend. Although it does seem to smoke a lot more than it did before and it seems to use more fuel. Last year I could pull a 3-person tube for 5-6 hours before my low fuel buzzer went off. This weekend it was going off after 4 to 4.5 hours. I run premium fuel and a bottle of Seafoam in every other tank full.
