What kind of stator is this?

[LonesomeTriZ]

I found this engine when I was going through my parts stock pile. I have no idea where it came from or what all has been done with it. I just noticed the stator is not stock. From what I can tell the rest of the engine looks as it should. Any ideas?

[SYKO]

can it just be a YZ stator?

[LonesomeTriZ]

I have no earthly clue. Why would it be different if it is? Unless it is from a different year.

[200xman]

I have no earthly clue. Why would it be different if it is? Unless it is from a different year.

It would be different since the YZ does not have a lighting coil. I would agree with Alan, that looks like a dirtbike setup.

[Mosh]

At first I was going to say it is a YZ stator.
But there are a few issues with that.

The Z crank, does not fit the YZ flywheels.(The YZ crank had a smaller shaft for the flywheel) The YZ stator and flywheel was smaller because they did not have the lighting coils on them.
I went thru this with my first Z engine.
I used a 86 YZ bottom end, but had to switch the left side crank journals to fit the Z Flywheel so I could keep my lights.



That engine would have to have a YZ crank in it for it to fit, the YZ flywheel.
It could be some sort of aftermarket stator and flywheel, because even the YZ flywheel uses the same puller tool as the Z, and I dont see the threads for that tool on your flywheel.
If it is a YZ bottom end, there will be the bearing installed in the case on the clutch side for the powervalve actuator, near the water pump shaft.
LOL..I just noticed, someone used wheel lug nuts for the jug nuts in your pic..

[LonesomeTriZ]

What good is it if it I cannot power my lights?

[LonesomeTriZ]

The first thing I looked for was the Powervalve traces. Unless I have been out of the game so long I did not see them, I do not think it is a YZ bottom end.

[dcreel]

It's also adjustable for timing. I don't know if the stock one is adjustable like that.

[Mosh]

The YZ set-up or Smaller flywheel will allow the engine to rev up faster, but lose some bottom end due to less rotational mass.(More suited for MX or Drag racing)

The yz stator and Z stator where both timing adjustable from the factory.


Even though, you dont see any exterior PV stuff, It still could be the YZ bottom end.You wouldnt know for sure unless you pull the Clutch cover and check for the bearing, or remove the flywheel and see if a Z flywheel fits.
If the Z flywheel fits, it is definately a Z bottom end or crank at least.

Either way, the ONLY mechanical difference between the YZ 250 and 85 years Z bottom end was the left side crank half.
Everything else was Identical, with the exception of the clutch cover and Kicker set-up and flywheels, which could be converted easily between the 2 different bottom ends.
I wonder if it is a IT 250 Flywheel and stator?
Rumors were that the IT's had the same bottom ends as the Z and YZ.
or maybe it is a YZ 465 or 490 bottom end?
Raffa may be able to help on that one.

[LonesomeTriZ]

The YZ set-up or Smaller flywheel will allow the engine to rev up faster, but lose some bottom end due to less rotational mass.(More suited for MX or Drag racing)

The yz stator and Z stator where both timing adjustable from the factory.


Even though, you dont see any exterior PV stuff, It still could be the YZ bottom end.You wouldnt know for sure unless you pull the Clutch cover and check for the bearing, or remove the flywheel and see if a Z flywheel fits.
If the Z flywheel fits, it is definately a Z bottom end or crank at least.

Either way, the ONLY mechanical difference between the YZ 250 and 85 years Z bottom end was the left side crank half.
Everything else was Identical, with the exception of the clutch cover and Kicker set-up and flywheels, which could be converted easily between the 2 different bottom ends.
I wonder if it is a IT 250 Flywheel and stator?
Rumors were that the IT's had the same bottom ends as the Z and YZ.
or maybe it is a YZ 465 or 490 bottom end?
Raffa may be able to help on that one.

My brain hurts...

[HondaHarry]

Looks like YZ125 to me.

http://cgi.ebay.com/ebaymotors/1987-YAMAHA-YZ125-YZ-125-STATOR-5_W0QQcmdZViewItemQQhashZitem5ad28908c5QQitemZ3900 79252677QQptZMotorcyclesQ5fPartsQ5fAccessories

[MTS]

I thought i red somewhere, they used to run the small stator and roter set up of the old Yz 50's or 60 dirtbikes....was a while ago.

[LonesomeTriZ]

Other than the weight differance, what would be the point?

[Racerguy381]

Its possible its an IT they did have the same size crank on the ignition side. Also it could be a KX set up I know they have a pretty good size crank end. Plus the pulser sits in the same position as that backing plate. Alot of the 125's even had large crank ends the ran a center bolt rather than a nut at the end. My bet is its probably still a Yamaha stator though if it has the factoy plugs still on it like HondaHarry pointed out in the link. That one looks like factory plugs on a Z. Here is a pic of a KX one just for referance.
http://i.ebayimg.com/21/!BQQqi8gBmk~$(KGrHgoH-DcEkJw1)bDiBJ352V!Vhw~~_12.JPG

[Bryan Raffa]

whats the vin on the motor... first... my guess it's a yz bottom end.. with a z top....vin will tell

[LonesomeTriZ]

I will go out there and get that after my run this morning.