I have a 2008 mercury outboard I bought used in 2013. It's has less than 100 hours on it and the coil went out. I was told that there was a recall on these coils and thousands have been replaced for free. However now Mercury will not honor this anymore. I was also told that even though only one is bad you must replace all four. Is this true and if so, why. The Ser. # is 1C064050 model 50ELPT

