Misfire on bottom cylinder at idle04 johnson 40 hp j40plsrs

"less than 100 hours,problem h

"less than 100 hours,problem happened suddenly,spark is present, adding carb spray to bottom carb opening does no help. removed carbs and cleaned,no debris found anyway. after running on lake at mid to full throttle,engine cleared out ran great until backing down to idle then after 10 secs or so engine appears to load up on bottom cyl and runs on top cyl and then dies.plug on bottom cyl appears lighter than top, if vacuum line on bottom of intake plate is plugged seemed to smooth out for a while. i think bottom carb is flooding out cyl at idle although plug is not saturated with gas. please help, much appreciated"

You simply must start with a c

You simply must start with a compression test! These 2 cylinder motors have a history of piston and ring problems.Report your numbers for further help.