Engine stuttering

[Scooter]

I'm still uncertain what part of the fuel pump assembly was at fault, since I replaced fuel pump and fuel filter as they came, all together. It took about half an hour to do the task. I will see if there is a way to test them.

I'd place my bet on the fuel pump. Fuel travels through a fine mesh screen before it even reaches the fuel filter and if there was enough gunk to plug up the filter I would think you would be able to see some of it sitting in the bottom of the tank.

 

[Rolando]

For a long while this problem did not present again. We were quite happy with our bike and trips. Thought the fuel pump change was the solution. However, this problem has presented again. Of course it could be the second fuel pump has again failed. However, it could be something else is going on. Re-reading this thread it's clear with your help this was a very thorough diagnosis. So, maybe there is something in the indicated pipes or other elements that must be checked. I will be having a look under the tank to check, though I'm usually very carefull and wonder if I will be able to recognize anything. Probably I should have bought the new fuel pump, rather than the recovery one. Thinking out loud here. (Rather, in writing.)

 

[BakerBoy]

Rolando, see posts ~34 to 45 in this thread for some discussion of the same issue on mine. A used replacement fuel pump did not solve mine, but a new fuel pump did. :yes: