OX66 Premixing

[jf123]

Both water and oil systems are protected. As long as the systems are functioning properly you will go into limp mode to prevent failure. If you really want to burn up an OX66 neglect the O2 and fuel system. They do not like being lean.

[bigfish1229]

no they definitely do not. i like the sound of of seizing more so than 2 or 4 rods coming through the bblock

[Tucker]

Rods coming through the block?? Holy crap talk about fubr!! Can't be much left to salvage after that happens. Describe that sound...is it pow! boom! or clank! jf please explain about running too lean. I thought that was the beauty of these OX66's. I thought the O2 sensor sent lean-rich, advance-retard signals to the computer. In short, the mixture & spark change on the fly according to your hand on the throttle. It seems to be the ultimate in fuel efficiency and performance.

[jf123]

The O2 takes a reading from one cylinder. If the sensor signal tells the computer I'm rich it adjusts to go lean. On all cylinders. Same would apply to a clogged VST. It senses lean so the adjustment would go rich. It has no idea the sensor is bad or a filter is clogged. Process inputs and send outputs. It's up to the end user to verify eveything is in spec. Technology is great but the human factor still has to play a role in order for it to work without flaws.

[Tucker]

Well you just touched on something that raised concern. Why does Yamaha put the fuel filter before the LP fuel pumps? I'm sure there's a good reason for it; but, you'd think it would be after the pumps as a last resort before going into the VST. What if a tiny piece of rubber diaphram comes off the LP pumps...right into the VST. I just upgraded to the Yam 10-micron remote F/S. Hopefully the VST is clean. My engine is 10-years old and the previous owner said the the tank has never been opened. Looks like I need to take it off and clean the screen on the pump. I'm reading posts that guys go through that PIA only to find the screen clean.

[bigfish1229]

pia? it takes 20 mins tops and will save a powerhead. sure seems like a reasonable bargain to me.

[Keys2fun]

Need how to help disconnecting the oil system

A little help please. Does anybody really know how to disconnect the oil system so that I can premix. I've had two sets of different mechanics from different shops disconnect various parts of the oil system and the motors continue to go on shutdown mode. The port motor is on high High Rev shutdown and the starboard motor om low shutdown mode. Neither mechanic has disconnected the oil tanks in the motor.

They left the old tank there and they trapped the sensors with tie wraps

A little help please with disconnecting the oil system on my 2000 Yamaha 250 ox66.

Thank you in advance.

[boscoe99]

Three snippets of advice.

Start your own new post.

Don't deactivate the automatic oil injection system.

Fix the problems.

[rodbolt17]

find real factory trained mokanics.
this old post was a hilarious read. I wasn't on this forum back then or I would have had a blast.