2004 Yamaha 250 hpdi only runs when key is held to start

[G.A.F marine]

2004 Yamaha 250 hpdi only runs when key is held to start. i disconnect the pin plug to bypass the key switch and its doing the same thing after i jump the plug on the engine side. i verified that it runs when held to start by disconnecting the starter wire from solenoid after the engine start any suggestions thanks in advance

[fairdeal]

Puzzling.
Seems like hkeyswitch problem.

So lets think this through.
What does the key switch do?
3 things:

- it switches the white 'kill signal' wire / ground connection

- it switches the yellow "ignition" wire / red 'always hot' wire connection

- it switches the brown 'starter motor' wire / red 'always hot' wire connection


what is the key switch not doing in the 'run' position -
but IS doing in the 'start' position ?

[G.A.F marine]

Hello Fairdeal thanks for the response. i disconnect the starter wire brown/white from solenoid so starter dont spin, I unplug the 10 pin plug from the engine. i used a wire at the engine end of the 10 pin plug and connect the red ,yellow and also the brown wire together then i TOUCH (not place) the starter brown/white to the solenoid and the engine starts, once engine starts i then remove the jumper from the brown wire only at the 10 pin plug engine end and motor runs for a second then dies . so in other words i bypass the key switch altogether only working at the engine end