Just to give you guys an update, I have actually put it aside for a couple of days and have been flying my focus since the weather has been so good. One thing I dont think I have mentioned is that I have taken the engine out of the plane and am using a test stand. What I plan to do is go over the whole engine again and check all the bolts and most importantly change the tank and the lines, and make sure it is insulated from the stand using foam. I will let you know how it all works out when I run my next test.

Ok guys here is the latest, I was not able to change the tank as the one I was going to use leaked and I did not feel like assembling another one, but the one thing I did not mention is that I had a Tetra shut off valve in the fuel line that fed the carb. I replaced that fuel line and removed the valve well guess what, the bubbles are gone. It ransitions well to 9100 then I backed it off to about 8800. I then did the 4000 test and it was fairly stable. But the idle is still not great, I can idle down to about 2800-3000 without the igniter and it will hold it for atleast a minute before it starts to slow up and die. I was running out of daylight and had to stop but I think if I keep the igniter on and get it down to 2500 or so I should be able to adjust the bottom end, right?

Keep the ignitor on it and adjust the low end per the instructions posted here earlier. If it slows down and dies after a minute, then it's probably loading up, so lean it some and see what happens. If you can get it to idle at 3000 or so without the ignitor, let it run like that for a few tanks full. Remember, this engine is still breaking in! It will improve with a little time, and you should be able to gradually zero in on the exact regulator setting, and begin reducing the idle RPMs until the regulator drops out and it's running just on vacuum. Take your time, make small adjustments, and once you get it to idle at 2500 or lower, concentrate on the air-bleed screw until you get it to idle smoothly. Often just a touch to the regulator screw will make all the difference in the world, and once you get it tuned, it will purr every time you start it.

It's amazing how often another part in the fuel system winds up being the cause of a YS that isn't running right. Just like my 140 was at first.

Good Luck!

David

Rule #1 is no fueler valves. I can't speak for others but I personally have yet to find one that doesn't wear and cause a leak.

As for your idle, it's rich and the engine is still breaking in. Run a few more tanks throught the engine and then we can dig in on the idle. Chances are the low end needle needs to come out a little.

Peted

It wasn't a filler valve they are the worst I have never seen one that worked, it was a shut off valve by Tetra. It was left over from the DZ engine. They say that a DZ will tend to flood if left alone for a while between flights. I used it to shut off the fuel when I was not flying.