Dave,

I've got a 63FZ that I bought in October 2002, I'd say it has about 2 gallons thru it (counting test stand break in) of Magnum Heli Mix (30/20 synth), and brand new OS F turning a 13/6 APC at 10,200 at about the same elevation you're at.


Anyhow Here's the problem:

I haven't really had the engine running relaibly at the field yet....yet in my yard It runs like a top... ANyhow, I'll start it up, adjust the main needle, and it's just running fantastic...smooth as silk. Then It just stops, like you're car when you turn off the key. I think it happens more around idle to 1/4 throttle... But it's also done it at half throtle and higher.

The tank is well pressurized and holds the pressure, all the filters look new still, I've tried a few new OS F's and no change.

I'm not sure if this is a factor but I did turn in the regulator screw about a half turn because the engine would load up and run rough as it transitioned from a little under 1/4 throttle to 1/2 throttle.

I'm pretty much stumped!

Thanks

Did you turn it in or out? Where is the idle needle set?
Also try a little less prop to run the engine at about 11000.

I turned the regulator screw in (clockwise) 1/2 turn. The main needle is at about 1 3/4 out. I don' t think prop size has anything to do with the problem.... By leaning the main needle a little more I can easily get it to 11000 with huge amounts of smoke still. It's really weird how it quits.... It runs fine and smooth, then just stops like if you snap the throttle closed. It's definitely not over heating either.....every time it happens the engine is pretty much average temperature, not on the hot side.

You need to run it closer to the peak. If you are backed off nearly 1000, it is just too rich and will quit just like you say. A couple of hundred rich is about right. May have to back out the reg when the HS needle is right.

Thanks Dave, I'll try that out

Dave,

I finally got some time to get out flying again... and damn... This engine is still giving me grief! I tried what you said....and still does the exact same thing... I even tried going down to the 12/7 APC tuned to turn at 11200-11300... Same thing happens.. I even reverted back to the base settings that you mentioned in a different post for the idle and regulator screws... and still the same thing happens... It just quits after a minute or so whenever the throtle is below 25%. I'm really getting frustrated since I've yet to get this engine to run reliably.... and it's not like I'm YS challenged... as I've had 3 YS's that were (and 1 still is) as reliable as a swiss clock!!

Better send it down so we can fix it.

Hi Dave,

I have a very similar problem with my FZ63 also. I've had about 2 gallons through it however. One day, the engine just started with this problem for no reason. I'm running a 12x7 prop. The same one I'ved used since break-in finished. I am also using the Powermaster YS20/20. I've already replaced the regulator diaphram and plunger. The lowspeed is 1-1/4 turn out. The high speed is 2 turns out. The regulator screw is 1/4 turn in from flush.

I've tried new #F plugs, new fuel, and re-adjusting the 3 different adjustments systematicly but nothing worked. The engine would either idle great and then stop abruptly during throttle or I can get the highspeed perfect but it would not idle or die at low speed.

Should I send this in also? Can you give me the address of where to send it to?

I own 2 other YS-91AC and 91FZ with no problems at all.

Thanks,
Rut T.

I think it should come in. Here's the address:

YS Service
1295 Industrial Court]
Gardnerville, NV 89410

Phone 775-782-4562

Dave; I own a YS FZ63. The problem I am having is on the regulator after running the engine then shutting it down the carb is filling up with fuel. What is the proper sitting on the regulator screw? I removed the diaphram and plunger cleaned it all everything looks ok but the engine is getting way to much fuel. Even when the engines running I can see it spit fuel. Britt

The plunger is not sealing. Screw the reg screw in 1/2 turn at a time until it quits doing it.

Thanks Dave I'll keep working at it. Britt

Let me know how it works out.