2008 yamaha f225a

[outboard1]

the motor wont idle at times.if i get it to run it would backfire through the throttle bodies.ive sincronised the throttle butterflies according to the workshop manual with a vacuum guage ,reset the tps & changed the main internal wiring harness,ecu,air intake pressure sensor,the high pressure fuel pump & relay.it would idle perfect at times.

[sachin2021]

Unplug the thermosensor and see if it behaves. If so you know what the problem is. Yamaha is now supplying these motors in Fiji with 2 replacement thermosensors. Should tell you something. My F150 had all these symptoms. Drove me nuts till I unplugged the sensor. Put in a new one and been fine since.

[boats.net]

Run a compression and leak down test, check belt timing is corect.