Bad stator symtoms ?

[islandman1]

If a stator on a 2000 Yamaha ox66 200hp was bad what would the symptoms be on the motors performance? Is a stator a common issue with this motor?

Thanks in advance for the input !

[boscoe99]

Let me answer your last question first. A stator failure is not common. Highly unlikely in fact. There are no moving parts within a stator, unless one considers the electrons. But, can and do they fail? Absolutely.

A Yamaha stator is usually an assembly. That is, there are several components integrated into one. There can be pulsar coil(s), the charge coil(s) and the lighting coil(s) all rolled into one.

Failure of the different coils will result in different operational problems. For instance, if the lighting coil(s) fail there will be no current to the rectifier/regulator and a battery will not be recharged.

[islandman1]

Could a faulty stator cause the motor to miss as if it were loosing fuel pressure? My issues mimic those of Dunepray on the forum.I have spent time chasing fuel issues. Changed mechanics and he thinks its a stator. Just wanting some feedback before I spend any more than I have chasing this problem down.

[madharchod]

these are the symptoms you will face
1. your engine will idle alright and start up ok and when put in gear may or may not run and stall
2.when you speed up it wont go any faster than 3500rpm and stall, and if it does go up it will be erratic and engine will cut off
3.you will have difficulty in starting again after the engine is heated up
4.when your stator heats up it looses to produce current as the wiring inside the stator is either shot or on its way to be burnt

[99yam40]

he is back and seems he is loaded as that makes no sense

[rodbolt17]

does your mechanic own a peak reading multimeter?
if he does not find a real mechanic.
if he does find a mechanic that knows how to use one.

stator output is simple to test can be monitored underway and Yamaha makes an adapter to test them.

or buy a stator and see what happens.

[boscoe99]

he is back and seems he is loaded as that makes no sense

Loaded on more than just likker I would say.

I thought that one could not post things on the internet if it were not true. How does he getting away with posting?

[rodbolt17]

stator failure on the OX66 motors for the two CDI charge coils will take out one bank.
there are two charge coils for the CDI mounted on the stator ring.
each charge coil provides the current to charge the capacitors for one bank.
lose a coil and you lose one bank of cylinder spark.

some of the early carbed 3.1L motors would start losing charge coil output voltage and cause random plug fouling.
this can be monitored with a peak reading meter very easily.
at about 60V peak output the ign coils start having difficulty making secondary voltage.

typically your going to see 150+ V peak when running.

most customers that have purchased stators over the counter own spare stators.

[boscoe99]

most customers that have purchased stators over the counter own spare stators.

You might want to clarify this comment. I doubt that some will get the significance of what you are saying.

Unless the term "throwing parts at a problem" is familiar to them.

[rodbolt17]

clarification

as MOST shops wont take a return on electrical parts.

MOST customers that purchase and install a new stator based on a cousins uncles ex twice removed mechanics advice, they install it only to find that was not the problem.

now that customer owns 2 stators.

the good one they took off and the new one they installed.

spare stator.

[islandman1]

Update: Took it to a certified Yamaha guy. I told him I thought it was a fuel line problem. He tested fuel pressure and it was good. Based on what I told him about previous repairs he went straight to electrical. Tested and found it was a stator acting up and was not testing properly. Replaced stator and now it runs great. I asked him how often this occurs with my motor and he said he had never had to replace one on this motor.This guy comes highly recommended and seems to have a really strong reputation. I just wonder what may have gone wrong with my first mechanic.

[Native 242]

Im having a issue with my 250 ox 66. Its bogging when i try accelerate over 2500 change manual pumps fuel line and filter. Clean injectors and ox sensor . Clueless now need help. Any advice thanks in advance

[boscoe99]

Im having a issue with my 250 ox 66. Its bogging when i try accelerate over 2500 change manual pumps fuel line and filter. Clean injectors and ox sensor . Clueless now need help. Any advice thanks in advance

Start a new post of your own. Provide the complete model of the motor.