Tweet
i have a 90 hp 2004 2 stroke out board that is sometimes cutting out when it is driven above 4000pm feels like it looses power no warnings come up on gauges and no alarms sound you cant restart the motor untill you dissconnect the yellow cdi bypass wire it than runs in limp mode have tryed a couple of new cdi's have put a new wiring harness in have checked thermo changed fuel hose still no good any one got any ideas
-
-
sb,
Check to see that the alarm is working. Disconnect the two wires that go to the thermo switch (about four inches from the switch) and short them together with the ignition on. The alarm should sound to indicate an overheat condition.
If the alarm does not sound, then you have two problems. One, a bad alarm and/or associated wiring. Two, the thermo switch is probably signaling the CDI that there is an overheat condition above 4000 rpm. The thermo switch could be bad and closing before the proper temp of 180 degrees f., or you have a cooling problem. The thermo switch can be tested in a pan of heated water using a thermometer and an ohm meter. A cooling problem could be a bad/weak water pump, a bad/stuck thermostat, a bad/stuck pressure relief valve. The Yamaha shop manual describes how to test all of these.
Hope this helps [img]smile.gif[/img] ,
Ken K -
thanks ken i found the problem was a stuck pressure relief valve it is now running to full revs again
thanks againComment
Comment