I have a 1999 OX225, (rebuilt 2.5 years ago) that has been performing well. Sunday as soon as it started it up it seem a little rough, normal initial smoking, then idled ok. I thought the motor lagged a little when I went to get on plane. Around 4200 rpm the motor skipped twice. This happened throughout the AM, so needless to say I didn't run as far as I had intended. Around noon the motor was skipping or missing more, especially over 5000 rom. I brought the boat in, (still idling ok) came home and pulled the plugs. All 6 were blacker than normal...almost looked fouled. Any suggestions where to look first?
I run one hotter grade plug than standard, I think 8's. I did add 10-12 gallons of gas 2 weeks ago on the way home from the lake, could it be bad gas. Also, yesterday, I thought I smelled gas twice. I intend to install new plugs this week. I am open to all suggestions. No real tune up was performed last year, just plugs and lower gear oil. The injectors were serviced when motor was rebuilt.