1996 BF90 rough idle after heatup

Just had carbs rebuilt (ne

Just had carbs rebuilt (new plugs and filters)and sync'ed by local Honda dealer. Motor runs like chanp at high and low RPM for about an hour....then gradually at low RPM engine runs rough and eventually will stall. Dealer thinks still might be a fuel system issue...is there coil or timing module potential to explain this? Once motor is cooled...runs like champ again??

they did not sync it right

they did not sync it right

"Try checking for a air leak a

"Try checking for a air leak at fuel line connector, the o-ring onside can leak and cause this problem."

"Honda Dealer has tried three

"Honda Dealer has tried three times on carb rebuild....seems that a needle valve gets stuck on one of the carbs??....ran today for three hours....all is fine, then restart after a short fishing break, bam…backfire through carb and rough idle, then something lets loose and it runs... ok. I’m fit to be tied!! Will discuss the air in fuel line possibility with the dealer. thanks."

Do you have a water separator

Do you have a water separator fuel filter on your boat?

"yep, also talked with the de

"yep, also talked with the dealer and he had already replaced the fuel line o-ring...."

"I have a similar problem with

"I have a similar problem with one of My BF90's. After warm up cylinder # 3 drops out. What makes it hard to troubleshoot is that it only happens after warm-up and is intermittant. Seems to Me if it were a carb issue then it would happen all the time (not just after the engine is warm)although I did go through the exercise of draining My fuel tanks/ replaceing filters, etc earlier this spring. The fact it is heat related led Me in the directions of an electrical issue (possibly something expanding as it heats up), but I have swapped most of the cylinder specific electrical components and the problem still occurs (furtunatly I have 2 BF90 on the boat so I can swap parts for troubleshooting)"

"I may have the answer....ran

"I may have the answer....ran boat Friday for 5 hours flawlessly, then had the poor running problem happened again,... called my Honda dealer from my boat and he had mechanic come out to the marina. This time I had an intermittent overheat/low oil pressure alarm....(but not always). When putting motor to neutral, then in gear again...problem went away. Mechanic said when this alarm occurs, ignition systems cuts out spark to one of the cylinder, to limit engine RPM. This could be caused by a bad sending sensor or thermostat. In any case, fuel going into a hot cylinder without ignition is definitely going to make the motor run badly. Monday they are checking this sensor to see if this is the problem....hope it is...and hope this might help you too."

"well they need to replace the

"well they need to replace the parts not re-sue parts!!

also HONDA DUDE told me if you sand down the needle rigges a tiny bit, it will not stick!"

"My problem became non intermi

"My problem became non intermittant yesterday so I pulled carb # 3 off and disassembled and cleaned . problem appears to have gone away for the moment. Fish net came in handy when I dropped some parts off the stern of the boat during the process. I suggest having an intake manifold gasket on hand, mine came apart during disassembly."