PS Drivin me batty!!

[TerryBelanger]

The motor ran perfectly fine for about a month, then started haveing the dreaded midrange leanout problem. I got LCint to work on it for me. He made my a filter that got everything fixed. Ran god for a month and then started runnin lean again. I got ahold of a overfow needle and installed it and also replaced the pump. Holy crap!! the first flight the copter had CRAZY power. Needles at high speed:2 turns even, overflow 1 1/4, and Low speed with te side of the screw slot about 40Deg counter clockwise from center. It got me excited so I tanked up again. This time it went lean during spoolup. And I mean CRAZY lean. I'm going to check things when I get home tonight. Lunch break time ran out! I think either the pumpt popped out or I didn't instal the needle correctly. The needle didn't come with any instructions, I just screwed it on. Or maybe I got trash in the filter.

I'll check things when I get home. If I can't find anything like that the I guess it's off to the YS waiting list.

[WillJames]

Sounds like an obstruction if it went from good to crazy lean between flights.

[DavidH]

I agree. Sounds like something in a fuel passage or the pump is loose from the backplate. The high speed needle sounds way rich. Mine are set like 1 1/8 turn open from fully closed. The return needle on mine is set 1 1/2 turn from fully closed plus 3 clicks open. The idle adjustment is about 5 degs to the left ( counter clockwise) of center.

David

[TerryBelanger]

I'm thinking more and more that the pump may have backed out.

Is there anything special about installing the needle or is it just a screw it on type of thing?

[WillJames]

My needles are about the same as your David. Main Needle is 1 and 1/8 - 1.25, Return needle is 1.25 and low is at mid screw. This is the same on 3 PS's I have, they are virtually identically needled.

2 turns should be slobberingly rich Terry. The other thing you may want to check and it failed once on mine is the little piece of tubing that goes between the pump and the backplate nipple. Clint knew immediately what it was replaced it and lean problem solved. It had a tiny split in teh line but was enough to make the motor very lean at times and run good at times.

The needle just screws on. OS recommends 1.5 turns out,(I'm pretty sure) Clint experimented and it seems like 1.25 is better

[DavidH]

Is there anything special about installing the needle or is it just a screw it on type of thing?


It is just a screw it in type of assembly. All you do is screw the brass piece out and then screw the needle assembly in. The check valve assembly stays in place just like it was when the brass piece was installed.

David

[TerryBelanger]

Replaced pump with a new one, replaced the line between the backplate and the pump, replaced ALL the fuel line, Dropped the engine and took every part out of it and cleaned it.


Still running Lean

[TerryBelanger]

Found the prob. Trash in the High end needle. I over looked it when I cleaned it the first time.

Thanks guys for your help

[WillJames]

EXCELLENT!!! Sounds like your good to go for a while!! :)