Dr Erik Richard,

long time no talk brother. Good to see you are still in the modeling group up there in Colorado. I'm in PHX AZ area now.

On your DZ:

Try going a bit richer (IN) on the pump. The funny double peak thing is common on the 140DZ's...You are likely a little lean. Since the needle has very little response from the 2.75 to 2 turns open the 2 clicks is probably a little lean.

Also a concern is metal floating around inside the engine. This will eat plugs as well. Bad bearings and the likes can be hard on plugs too.

I would richen the pump (IN-CW) say 1/2 turn and then re-peak Back it off about 200 -300 rpm from that peak value. It might be 3-4 clicks rather than 2 clicks. The 140DZ has a pretty flat spot on the needle like you describe. The too rich to too lean is a broad band say 1/2 too or more but you want to be closer to the lean side than the rich side.

I don't have any direct experience with the newer PowerMaster DZ blends...I had trouble early on 2002 and went to the Cool Power from the Powermaster at the time. I'm sure the newer stuff for the DZ's Powermaster is good...I know a few guys that are running it. Mark Atwood (ohio) is one and I also Dave Villwok (Pac Northwest) was running PowerMaster as well.


I always found my 140DZ ran best a little richer on the pump and a little leaner on the HS. I was around 1.25 turns on the HS and about 1/2 to 1 turn in from flush on the pump.


Try that and let me know. You can find me over in the YS engine forum regularly. I don't always hit the pattern forum forum...but I have been helping out Richard and YS Parts and Service over in the RCU YS forum for a little over a year now.


Troy Newman