Yamaha 2004 60hp keeps foweling plugs?

[IcantDo55]

Drops a cyclinder and runs like crap. Why should this happin with only 20 hours on the plugs. They come out all foweled and after replaced motor runs fine. Any ideas. He's running the Yamaha NGKs that the book recomends. Is there a better plug>?<br /><br />Its a friends motor. I'm an I/O guy.

 

[WillyBWright]

Re: Yamaha 2004 60hp keeps foweling plugs?

Plugs should last for years. He's getting too much oil or gas. All plugs fouled leads me to lean more towards too much oil. There are multiple carbs and it would be odd for them all to be problematic, although varnishing affects all. How does he run the motor? Balls to the wall, or idle all day?