Hi Dave. A friend of mine who has no internet access at the moment asked me to throw you a couple of questions about the 140DZ pump. He opened it up to inspect the diaphram and found it had a couple of tears or cracks on it. The problem is now he cant put it back together because he forgot which plunger goes up and which goes down. also he is asking if the plunger spring goes inside the neck of the plunger like the other YS engines or is it on the opposite side? I told him that the spring goes inside the neck like on all other YS engines but I have no idea on the plungers as I have never taken apart a DZ before. Can you help? Thanks.

Didn't you get an instruction sheet with the engine? There is an exploded view of the pump on it. Failing that try www.ysperformance.com for a PDF of the instructions.

Hi Dave. Its not my engine. Just posting for a friend. He bought the engined used but it just came from Richard and was just serviced. Will just pass on the message to him. Thanks.

Good Luck!

Hi Dave! My friend says he managed to get a new pump from Hong Kong. One last question, which is the newer version of the pump, the one with or the one without the grooves on the plunger? Thanks.

No idea. YS makes changes in parts sometimes and never bothers to tell us.

Sorry.

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.

As I said, we don't always have current drawings as YS never updates the drawing even though they have made a parts change. The pump you have is likely from a 160. I'll see what I can find out.

Thanks a lot Dave. Hoping for your earliest reply.

A really big YS fan!