1986 Yamaha 175 running rough

[brodie129]

Just had a new battery installed. Left ramp went about a mile out slowly increasing speed to about 3500 rpm. All of a sudden the engine alarm went off and the engine was running rough real bad. It was smooth at idle, no lights on dash peeing fine. We went slowly back alarm still going off. Took top plug out looked clean, bottom one dark, same on both sides. Any ideas what could be wrong???

 

[R_P]

Sounds like it went into “save myself” mode possibly from overheating or if a precision blend maybe no oil (if so equipped). Just because there is water out the telltail does not mean it is cooling properly.