ox66 excessive oil in chambers

[tbtech24]

Default ox66 excessive oil in all cylinders



Yamaha s225txrx. Had a lot of carbon built up on the o2 sensor. The motor would jump from 2200 to 3300 rpms without moving the throttle. Also was very hard to start. Once I cleaned and bench tested the o2 sensor and reinstalled, the motor ran great and started right up for about 3 mths. Now the motor has a lot of oil in the chambers. The spark plugs and o2 sensor fouls out with oil all over them. I did a sync and link on the throttle body. Checked the tps and crankshaft position sensor. Adjusted the oil link rod. It was still set at the original break in from the dealer. Checked spark and compression. All good. The o2 sensor bench tested good. I checked the spark plug boots and some where out of spec. I would think if those are the problem then it would be isolated to the cylinders that the spark plug boots where out of spec. Not all the cylinders. The motor still fires up great but shakes at idle and while increasing rpm. Also at top end the boat goes 44mph. The motor will lose a few hundred rpms and drop the speed down to 39 mph until you back off then it sometimes goes back to wot. The vst maintains pressure even when the issue occurs. It also has bean cleaned. The lp fuel pumps where replaced because of one leaking. Replaced spark plugs as well. Still runs rough and shakes at idle. I pulled the fuel rail and inspected the injectors. Looks clean and good. I don't know why there is so much black oil on the piston heads and the chambers as well as the spark plugs and the o2 senor. I have a d.v.a. coming in a couple days to test the stator. Im lost on the cause of excessive oil.
Thanks for any help

[rodbolt17]

do you understand how oil gets from the engine oil tank to the cylinders?

also, there IS and WAS no break in setting on the oil link.

that is just another internet myth.

[tbtech24]

the manual stated to have the lick .04" between the oil link cam and the oil link stopper. The oil is mixed before the vst correct?

[Tucker]

How about the seal on the oil pump drive shaft? Engine vacuum pulling oil right into the crank case.

[rodbolt17]

with the throttles FULLY closed, NOT at idle.
the clearance between the arm and stopper should be .005-.020.
most required trimming the arm to obtain it.
most dealerships never checked it.

yes the oil is mixed in the VST.

the ECU does NOT control oil.

the O2 sensor should be cleaned and tested every 200 hours or once per year.

[tbtech24]

The o2 sensor was cleaned ohm and voltage tested. All passed. The oil link rod is adjusted to .004. I lost power to the starboard coils. port looks weak now. Before I had good spark across the board. If the starboard bank is out would that be the stator or the pulser coil?

[tbtech24]

im not sure what wires to check with dva on the stator and on the pulser coil

[tbtech24]

Its the same wires that you ohm test just use volts setting with dva and go to ground right?
What about the three green wires? Same?

[rodbolt17]

the 3 green wires are for battery charging only.
that engines stator, no matter what the manual says, uses one charge coil per engine bank.
lose a charge coil lose a bank.
the pulser coils each control a single cyl.

the CDI does NOT amplify stator voltage.
it simply stores in in a capacitor and discharges it through the ign coil primary windings.

[tbtech24]

the charge coil is part of the stator on this motor correct?

[Tucker]

Voltage leaves the stator, goes to the charge coils and then to the pulser coils. Do the charge coils step up the voltage going to each bank of pulsar coils?

[99yam40]

Voltage leaves the stator, goes to the charge coils and then to the pulser coils. Do the charge coils step up the voltage going to each bank of pulsar coils?

everything under the flywheel could be called the stator
There are pulser coils, charge coils, and lighting coils.
they all produce different voltages, but do not feed into each other

[tbtech24]

right but if the charge coil is bad then the stator assembly needs to be replaced because the charge coil is part of the stator assembly not the pulser coil correct?

[99yam40]

looking at the parts break down of your motor , they do not show the charge coils separately so I believe you are correct it is part of stator

[tbtech24]

Charge coil failed resistance test and low speed voltage check. Time to replace the stator.