Oil Injection System Bleed after Re-build and O2 Sensor

[cpostis]

SX150TXRZ- Yamaha Service Manual says after supplying 50:1 to fuel filter inlet:
"Disconnect oil pump link rod joint, start engine, and turn oil pump lever and keep in the fully opened position until the fuel/oil mixture flows out the oil pump feed hoses."

Yamaha Technical Bulletin O99-024 says:
"Some acceptable methods with older technology could adversely affect new technology regarding the O2 sensor. There are two older technology methods that have very adverse affects on the O2 sensor, they are:
• The use of too much oil mixed into the fuel during break-in.
• Disconnecting the oil link arm when bleeding the oil pump.
Always follow the most current procedures for break-in and engine set-up. Do not disconnect the oil link arm when bleeding the oil pump."

Rodbolt, Boscoe, what is your opinion/advice on this. Putting my lower unit on and will be ready to fire her up today. Please reply! Thanks!!

[boscoe99]

I am not seeing in 99-024 what you are saying is in there.

Anyway, I would simply run the motor on a small portable tank of premix fuel at a 50:1 gas/oil ratio. Prime the VST until it is full of the premix. Turn the key on and off several times to help bleed and prime the fuel system. Keep the VST full of fuel by using the primer ball as the fuel pump sends some of it to the fuel injection system.

Disconnect the oil pump link rod. Turn the oil pump lever to the full oil position if it does not default to the full oil position on its own. Start the motor and let it idle until all of the oil lines have been purged of air. The oil line to the VST can be removed and placed into a container that will catch the oil. You can readily see when the air has been purged.

If you are concerned about disconnecting the oil link rod then just don't do it. It might take longer to purge the oil system but the extra time should not be much.

Regarding contamination of the O2 sensor, it is only going to be seeing the burned 50:1 gas/oil mix since the air/oil that is being purged from the oil system is not going into the VST. If you have concern about it then when the oil system is purged of air you can drain the VST of the premix and use the primer ball to refill the system with straight gasoline.

Don't forget to hook everything back up once the oil system is purged of air. Oil link rod, oil hose to the VST, primary fuel line, etc..

[cpostis]

Sorry, I had the wrong tech TB #. It is O99-008. See the attachment.
Thanks again, and unless I here different I'll follow your instructions.

[boscoe99]

Let's see what rodnut has to say.

Yamaha USA has bulletins that sometimes contradict what Yamaha service manuals have to say. And then Yamaha mechanics out in the field may each have their own separate ways of doing things.

[rodbolt17]

here in the US.
we just bled the oil pump while running using the pump bleed screw and ran the first 20 or so gallons at 50/1.