I have a 1999 90 hp Johnson outboard model number J90pleeb that is having problems running continuously at idle and high speed. I suspect the fuel is bad as it has been in the tank for over a year now with no stabilizer added. I have taken the tank out removed all gas and cleaned throughly. I would like to replace the fuel filter, but not be to mechanically inclined I'm not sure where or how to do this. Any help would be greatly appreciated. Also should I replace the fuel lines from tank to engine? Thanks for any help or suggestions you may have!