I have a 90 hp J. and have had it since 1/05. The previous owner had mentioned that he had these replaced once a year. I had a 48 spl J. bought new and had motor for 3 years and never replaced these.<br /><br />Obviously this is an older motor...but how often should this be done. If I take it to a shop how much should I expect to pay for this?<br /><br />Thanks in advance.<br /><br />Ric