Dave:
I am having probles with my 63, will die during flight. YS 20/20 Powermaster fuel, 12/4 prop, YS plug. Have checked for blockage, replaced regulator spring, diaphram, plunger and the rubber plunger seat. My question is, I had the pressure housing off so many times, I forgot which way it goes back on the engine. One side of the housing has a buildt up rib on it. Does this face the prop or the engine housing? Question #2, I ordered the plunger from Central Hobbies twice by part number off the instruction manual. Both times they sent me a smaller diameter plunger, about 1/2 the diameter that was previously in the engine and it had a different part number. Has the plunger been changed in both size and part number?
Thank You
Paul Eagon

Dave:
Another question. The plunger spring. One end is wider than the other. I assume the the small end goes over the rubber plug and the larger end goes towards the adjustment screw. Correct?
Paul

Dave is out of town until Monday.

He'll answer you when he returns; I have the same question...<G>

Steve

First of all, the bump on the regulator casting goes forward.

The plunger with the small head is the one to use. They made a change in the part but not the part number. We never like the big headed one.

Question, Paul. Does the engine die rich or lean? At what throttle setting?

Let me know.

Steve. Got your engine. Will check on it's progress in the am. It may already be on it's way back to you.

Dave

Dave:
The engine loads up with fuel during 3/4 or less throttle when flying and dies rich. I have to run full throttle to clean it out. I have the low speed adjustment as far out as I can and have experimented with screwing in the pressure ajustment screw. Have been waiting for your response prior to tring again. Also, on my question #2, what is the correct plunger spring direction, large end versus small end?
Thank You
Paul

The plunger spring goes small end toward the plunger.

Reset the idle screw to 1.5 turns open. Reset the reg screw to flush with the casting. Start the engine at just above idle and let it run for 30 seconds. Go to full throttle and set the high end. The needle should be open about 2 turns to start and should be about 1.5 turns open when set correctly. Go back to idle for 15 seconds and note which way the engine wants to go, lean or rich and adjust the idle accordingly. Then advance the throttle and note the transition, too lean open the reg screw 1/4 turn at a time to richen. If too rich go in 1/4 at a time.

If none of this works, box it up and send it to our service dept. because it need help.

Dave

Dave:
Thank you for you advice. I tried the settings you recommended and am still having problems with loading up and quiting in the mid range. Engine runs great at idle and top end. I have packed up the engine and sent it to you with a copy of this thread
Thanks
Paul Eagon

pceagon,
Just wondering.
What kind of rpm range do you get with 12x4?
Looks like you may have over reved the engine.
Most people including myself use APC12x7 for start. 13x4W for 3D.

PatternFlyer
Just tried it once to see how it would do in hovering. Was careful not to over rev. Normally use 12x6. It was actually a 12 3/4 X 3 3/4 wide apc. Did not try to tack it as I was having problems before using this prop.
Paul

Dave:
Received my engine back today and am very pleased with the quick turn-a-round. N/C for the repairs??? I was more than willing to pay for the repairs. I noticed you replaced the rear bearing (Inv.#YSP203104 of 3-3-03). Is there something that I may have done wrong to cause this problem?

Thank You again, your service is appreciated.
Paul Eagon

Hi Paul,
If there was a problem that YS caused, the repair is at no charge. I can't imagine anything that you did caused the rear bearing to go bad, but obviously Rich thought he had better replace it. I don't know, as I seldom work on an engine other than my own.

Good Flying,
Dave

Hi Dave , is the plunger with a diameter of ~10mm the big, old one?
Rgds andré

That would be the large size.