Yamaha Star 650 Fuel System Testing and Troubleshooting - From The Fuel Tank to the Carbs

In todays video we will be going through the complete fuel system from beginning to end to identify problems from within the system that might be causing issues with the bike. This demonstration is conducted with the tank removed for ease of viewing and conducting the demo.

In the first half of this exercise the assumption is that the delivery is hindered or corrupted by foreign matter requiring testing of flow from the tank and requiring possible parts replacement at the fuel valve and onward towards the furl filter as well. As a follow on to this, if flow could be achieved an instruction of purging the system of old gas is demonstrated so that all of the old gas is not re-introduced into the carbs.

The second half of this video deals with the normal sounds one hears when the key is heard and run switch actuated, this, which can point towards a possible fuse issue if an expected sound is not heard leads us to check all of the fuses in the fuse box. If its determined that all of those fuses are good, a further check of all electronics can be made by running gas right to the carbs and starting the bike that way, a good test to rule out the switches, relays and ignitor.

This doesn't fully rule out the pump or electric to the pump though, because if all of that worked, we should see the 12vdc at the pump connections on startup, so we gain access to the pump connector to check both the resistance of the pump as well as the expected voltage. If the resistance of the pump is infinite or short, well, its gonna have to be replaced. If there is no battery voltage when power is applied, then there is an electrical issue to trace.

If its determined to be the pump, we demonstrate the removal of the pump from the bike as a unit replacement for resolution of the problem.

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