im at my witts end with this , first i just bought the boat , runs great when first leave the dock , idles great smooth good throttle up , great power , after run awhile when pull back to idle it will caugh then stall , followed all the postes about carbs cleaning fuel pumps and fuel lines filters , ok did carb cleaning they were clean to start with looks new , but did anyway , 2 new pumps , all new fuel line and filter , and primer ball , new plugs , whew 3 days later went to test run and wow it ran so smooth and i thought it was fixed , till i returned to dock and let idle , then caugh and spit then idle slowly goes from 800 to 600 to 400 then stalls , restart idles up to 1200 then slowly comes down then spits then stalls.......... ok thinking it may be carbs , i have another boat that is my friends that has same engine that runs perfect , he alowed me to change carbs to test , guess what same stalling after switching to his carbs , just for laughs i ran my carbs on his boat and yep u guessed it it runs perfect. im lost please help. also my engine runs perfect on cruise speed and has awsome throttle snap no lag , IT JUST WONT IDLE ! please help.
forgot to say it smells rich when i rev it after it idles for a few min's
i did try to adjust the idle screw on middle carb , just makes worse it will run rough then stall , then i tried to jack up the idle on the throttle arm it will run ok 1000 rpm but dont wanna run that high , what the ??? im lost on this one........
Check to see what the timing is doing on yours and his to see if there is a difference.
I know on my C40 the idle timing was too far retarded and I had to change out the CDI because the TPS is part of the CDI on mine and was going bad
Sounds like you need a proper link&synch on the carbs....you may have a fuel pump or pumps going bad....yamaha says replace them every two yrs.
if memory serves....they usually last a lot longer, but you are going on eight now....not very expensive and pretty easy. When they go bad they may
not put out enough or like what you have, they may let raw fuel into engine as they actually run off crankcase pressure, if holed diaphragm it can leak
into engine at idle....causing rich mixture to kill engine....