Any thoughts on low idle problems?

kraken · #1 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 · #2 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

kraken · #3 08-20-2009, 10:04 PM

Quote:

Originally Posted by spareparts

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 · #4 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.

steplift20 · #5 08-19-2009, 10:38 PM

change your fuel filters, it might not be your problem but it wont hurt