Power cut in mid RPM

[brettfz6]

Hey there, I'm new to the forum I ride a 2004 Yamaha fz6 and it's been great except the past week in first and second gear when I give full throttle quickly the bike cuts power mid RPM and lunges me forward then gets back on power around 9k. It has new spark plugs, a recent oil change and the compression in the motor is good. I was told it might be something with the wiring because I forgot it I. The rain one night but I didn't think it would be affecting it still if it's from water. Has anyone ever seen experienced this on their bike before and if so what was the culprit? Also would it be wise to replace the wiring loom with a new OEM one?

 

[Gary in NJ]

Good looking bike, welcome to the forum.

Don’t start throwing parts at the bike, let’s try to understand the problem first. Motorcycles are designed to spend many days in hard rain and run perfectly. With that said as a bike ages, seals and other parts that are designed to keep water out, start to dry and shrink making them less effective.

You can easily disconnect the various connectors in the harness and inspect them for water egress and corrosion. While you have the connectors apart go ahead and clean them with contact cleaner. Put a light bead of dielectric grease around the perimeter of the female connector before reconnecting to be sure water doesn’t get in there in the future.

I would start with the connectors on the ECU as it is most likely to give these types of troubles. I would also do a resistance (ohms) check on the coils themselves.

Also, you may have some water in the fuel if the seal at the filler cap is cracked and dry. Worth inspecting.

Be methodical on your approach, troubleshooting is mostly a process of ruling things out.

 

[brettfz6]

Thanks mate! I really appreciate the advice I'll check all above mentioned this week! Crossing my fingers I'll find the issue.

 

[grahammarsden]

Have you checked the Throttle Position Sensor?

Go into Diag model and check that it scrolls smoothly from 15-17 when fully closed to 97-100 when fully open.