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I have a 03' FLSTF carburated and Im getting the check engine light while im riding. It comes on and goes off periodically during riding. Does anyone know what all can cause this light to come on. All my fluid levels are ok and I dont know what else to check. Also why does a carb. bike have a MAP sensor?

Well, as for the MAP sensor, that's for ignition timing.

As for the check engine light. Does it make any unusual sounds/ticks/do anything strange just before or while the light is on?
I'm not familiar with H-Ds dummy lights, so I'm guessing it could also be an oil light possibly? If so it means your oil pump could not be putting out enough pressure and going on you.

Do you do anything just before the light comes on? Like hard acceleration? Prolonged idling?
Wrider

check ur air intake system

map sensor is for air intake, its 2 little wires that vibrate measuring the amounts of air coming in.

when ur accelerating if ur a little short on air it'll let u kno, check filter, etc.

otherwise ur gonna have to be more specific about the symptoms.
any chugging, or low idle, nething?
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Grief or Loss Forum

I'm also stumped. Why would a carbed bike use a MAP (Manifold Air Pressure) sensor? It (or a Mass AirFlow sensor) is usually used for metering fuel in an injected system.

Hey Wrider, can you expand on how manifold pressure is used by the ignition system? That's a new one for me. Of course, I usually work on older bikes and airplanes without all those gizmos.

MAP = manifold absolute pressure
MAF = mass airflow sensor

a map sensor tells the computer the load being put on the engine (at idle the vaccum is high so the map sends a voltage to the ecu saying dont spray alot of fuel cuz we're only idling)
and then as u mash the throttle.. vaccum goes down, and ecu dumps fuel. So im confused as to why a carbed bike would have a MAP....

first the original post. Harleys run j1850 bus OBD just like a car. Yes harley(along with BMW) has the most sophisticated electronic systems on there bikes. go to your dealer and down load the codes. then you will see what the problem is. It has nothing to do with your fluid levels. thats what the oil pressure light is for. half the time the codes blown are nonsense. like "ECM power loss", or "ckp error", which is starter kick back. cant have a negitive reading.
Second. whats the MAP for. it gives an engine load reading. it signals the ignition modual for spark timing map selection or just timing. before HD used a VOES. Vacuum Operated Electronic Switch. there are computers on carb bikes too.