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View Full Version : Any thoughts on low idle problems?


kraken
08-19-2009, 05:30 PM
Just got the boat home and was told that the boat ran fine at mid and high rpm levels but would run rough and cut out at low levels. I am thinking clogged jets but open to more suggestions. The motor is the inboard/outboard mercruiser 470.

spareparts
08-19-2009, 08:33 PM
rebuild the carb, if it is a Rochester 2bbl( has two idle mixture screws) then you are ahead of teh game. If it is an early Mercarb(one idle mixture screws and uses a double diaphram accelerator pump) then you need to look for a Rochester or a late model Mercarb(has a single lip accelerator pump like the Rochester) that came off of a 3.7 L or 165. Whiel you are at it, replace the points with a pertronix electronic ignition kit, its an easy swap, well worth the money

steplift20
08-19-2009, 10:38 PM
change your fuel filters, it might not be your problem but it wont hurt

kraken
08-20-2009, 10:04 PM
rebuild the carb, if it is a Rochester 2bbl( has two idle mixture screws) then you are ahead of teh game. If it is an early Mercarb(one idle mixture screws and uses a double diaphram accelerator pump) then you need to look for a Rochester or a late model Mercarb(has a single lip accelerator pump like the Rochester) that came off of a 3.7 L or 165. Whiel you are at it, replace the points with a pertronix electronic ignition kit, its an easy swap, well worth the money


the boats year is an 82 and the motor is the original mercruiser 470

Lamont270
08-29-2009, 01:25 PM
Don't know if it is the same problem but my 82 470 was doing the same thing. I rebuilt the carb and played with the idle jets but it still would cut out. I talked to a mechanic and we reset my point gap 22 thou I beleive and have not had a low idle problem since. Just somthing to chew on.