PhotoAl
Junior Member
Picked up a 2003 Honda Metropolitan a while back. It is a big 49cc scooter - can you say s p e e d!
When they key was turned the bike would power up for a second or two and then shut down. After much checking and investigating I discovered the problem:
The stock electric fuel pump had been replaced by a mechanical pump.
The electric pump was in place but had melted and the coil had actually melted out of the housing and fallen off and was gone.
The computer (yes it does have one) looks to see if a fuel pump is in place by detecting current to the fuel pump.
Bought a new electric fuel pump - it would click once and that was it - didn't work. Seems like the computer should pulse the fuel pump but guess that part of the circuit was not working.
Through a trial and error process to determine the max value (for lower current draw and thus less heat) replaced the electric fuel pump with power resistors fooling the computer into thinking it is there and working. This keeps the main power energized and the bike will run. The mechanical fuel pump was retained and is what pumps the fuel. The mechanical fuel pump uses the crankcase pressure pulses to actuate a diaphram which pumps the fuel - pretty cool concept and common in scooters - have seen them on racing karts as well.
Bike runs good, only problem is my daughter thinks she is taking it to college to ride . . . guess I need to be looking for another scooter!
Top speed is 39MPH a blast to ride but have to leave the ego at home!
PS: it was a scooter shop that actually added the mechanical fuel pump and left the electric pump installed to burn up!
When they key was turned the bike would power up for a second or two and then shut down. After much checking and investigating I discovered the problem:
The stock electric fuel pump had been replaced by a mechanical pump.
The electric pump was in place but had melted and the coil had actually melted out of the housing and fallen off and was gone.
The computer (yes it does have one) looks to see if a fuel pump is in place by detecting current to the fuel pump.
Bought a new electric fuel pump - it would click once and that was it - didn't work. Seems like the computer should pulse the fuel pump but guess that part of the circuit was not working.
Through a trial and error process to determine the max value (for lower current draw and thus less heat) replaced the electric fuel pump with power resistors fooling the computer into thinking it is there and working. This keeps the main power energized and the bike will run. The mechanical fuel pump was retained and is what pumps the fuel. The mechanical fuel pump uses the crankcase pressure pulses to actuate a diaphram which pumps the fuel - pretty cool concept and common in scooters - have seen them on racing karts as well.
Bike runs good, only problem is my daughter thinks she is taking it to college to ride . . . guess I need to be looking for another scooter!
Top speed is 39MPH a blast to ride but have to leave the ego at home!
PS: it was a scooter shop that actually added the mechanical fuel pump and left the electric pump installed to burn up!
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