200 hp 2003 2 stroke ox 66 fuel injection idles at 1200.motor should idle at 600-700.any help appreciated
help !! high idle 03 ox 66 fuel injection yamaha
- Thread starter ray leonard
- Start date
Good question.Winged Pig said:
here is what I would look at:
First, disconnect the throttle cable linkage at the motor clevis pin. Start and warm the motor to see if the idle goes down. If it does, you need to adjust the cable or possible replace it. When warmed, try adjusting the idle screw to lower idle to about 730 revs warm
Check synchronization of throttle plates. You have to remove the silencer, disconnect the throttle cable, make sure the idle adjust screw is backed out and then look at the throttle plates to make sure they are seated correctly. Individual throttle plates may need adjusting.
Third, if the temperature sensor is bad, the motor doesn't know it has warmed up. That can cause the fast idle to stay active. Failures of the temp sensors are not all that common.
Those are the more common causes. Hopefully it is a simple cable adjustment
The reason I asked is I once pulled a cowl off my OX66 225 to check things out and when I put it back on it disconnected a green wire at the rear of the motor. Motor started up just fine but would not idle down. After looking for the problem and re-connecting the wire (plug connection) everything returned to normal. Lesson learned for me.
Anyway, hope that helps.
Anyway, hope that helps.
There is a connector that can be disconnected to force the motor into a special mode. Basically, all the logic of the ECU are overridden. This mode can be used when the EUC fails at sea. I have to check and see if the connector cable is greenWinged Pig said:
For my model year, the overide cable is yellow. You disconnect the connection on the back of the motor. The motor will run at high idle in this mode.
I don't know what the green cable mentioned connects to.
I don't know what the green cable mentioned connects to.
Here are some pages from a Yamaha Service Manual that may help you out. This manual has been invaluable for me with my OX66. You should purchase one if you like to do your own engine work.
Hope these help...
Hope these help...
thanks for all the replys.just bought motor n hung n fired this week.previous owner said it ran great when last run in 2010.started on muffs n idle was at 1200 only let it run for a minute or so.wasnt maintaining a steady water stream on muffs so we shut it down.had a 150 ox 66 fuel inj n it never cold started idle that high,that in mind i was concerned.what cold idle # should i have ? we'll try n splash this wknd n let motor run for 10 minutes n see where idle falls.we did disconect linkage n idle did'nt change,having us beleive it is correctly adjusted.
They idle at 1000-1200 when cold and settle at about 700RPM. They behave a little different when fully submerged, don't know why.
The fast idle works on advancing timing, that has to be disabled. Then it's adjustments. Do the OX66s run all 6 cylinders when idling, my HPDIs don't. That's a position sensor in the linkages if so.
The idle speed adjuster screw end should be against (contacting) the tab at this time as well as when you bought motor, when in neutral, and you did the linkages correctly to your control, the other adjustments would not be involved if the motor was working properly before. Before you start turning any screws just note each screw where it was prior to moving it and how many turns etc you did in what direction.
Make sure the neg lead from battery is solid connected to motor and battery.
The idle speed adjuster screw end should be against (contacting) the tab at this time as well as when you bought motor, when in neutral, and you did the linkages correctly to your control, the other adjustments would not be involved if the motor was working properly before. Before you start turning any screws just note each screw where it was prior to moving it and how many turns etc you did in what direction.
Make sure the neg lead from battery is solid connected to motor and battery.
I should call it the thottle adjuster screw as indicated in the diagrams, not idle screw. Old school habit with carbs!