YZ125L engine or K,L,N bottom end complete

[Ando]

Looking for a good engine or bottom end. 0404060523

[Ando]

Bump!

[alexbrown64]

K and L,N engines had quite a lot of differences as i found out when i was re-building my K engines.
I have quite a few L engine parts if your interested, which are different to the K.
L engine cases in good condition.
L clutch cover OK.
L clutch in good condition, needs plates
L water pump cover and parts in good nic.
L exhaust pipe in as new condition.
L crank needs rebuild.
Should be able to find a spare gearbox and assortment of other engine parts.

Check out my rebuild pages here... http://forum.ozvmx.com/index.php?topic=36259.90

You will see most of my K and L engine parts in these pages.. if your stuck, i can put together a package of parts.
Cheers,

[Ando]

Hi Alex,

I read alot of your 125k rebuilds as you were doing them, well done! If you look at the parts diagram you will find most of the gearbox parts other than the clutch from K to L supersede. What were the main diffences you found in the gearbox?

[alexbrown64]

Nearly all the engines and parts i bought were over 30 years old and most had been modified, converted, changed, damaged or stuffed.
I have the K manual, and the Partzilla page for the clutch and they both show a helical cut primary gear.

http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1983/YZ125K/CLUTCH/parts.html

This means your governor needs a helical gear and your primary gear on the main shaft.  However, i just checked again in my shed, and i have a clutch that has 24x on it which is straight cut, and a helical cut clutch that has 5x4 on it.  Go figure?  Perhaps Yamaha was updating parts and numbers throughout the first year.

I believe that most of the engine parts are interchangeable, including transmissions, as i have had a mish mash of parts inside.  You just have to be aware of what parts affect other parts, such as helical and straight cut gears etc. 
For example, the L has larger cylinder studs in the cases.  One of my engines had the K cylinder drilled to fit the L studs and now its all cracked around those points.  It fitted but it may of been better to get reducing studs to fit the K cylinder. (i have this cylinder on the shelf).

I do know that the K engines were supposed to be better than the L and N engines, so i would try to get as many parts, such as cylinders etc from the 24x.  I do believe that you can make the clutch, transmission, water pump etc.. work interchangeably as long as you have some of the corresponding parts.  I even have two shift drums from different models (1 with a removable bearing and 1 without) that both seem to work OK.

Hope that helps.  I do have a bunch of parts at home, so i can check numbers, sizes, measurements etc.. or sell you some stuff if your stuck.

Cheers,
Alex