Hi Dave! Finally, I get to post directly, Thanks Jay.

I don't know Dave if you have noticed it, but, the 140DZ manual on the ysperformance link is not the same as the manual included with the engine.
The ysperformance manual has the spring on the disk side of the plastic plunger(see pump detail), while the manual that came with the engine, has the spring inserted on the plastic plunger leg.

Please clarify, Thanks.

As Jayjay said, I have two 140DZ pumps, one having a grooved steel plunger, and the other which had none. I hope you could eventually update us on which of the two is the newer version.

Thanks for your guidance.

A very big YS fan.