I have a YS45FR mounted invert on a Dash45 pattern. The ship has been idling for over 15 years. Engine had less than 1 hour.
Recently I had the engine overhauled at YS Parts and Service in Nevada..........replaced the rusty front and rear bearings, regulator diaphragm and gaskets. Richard said the engine ran fine on his test rig before shipping back.

I got it back and could start it for 3-4 times on the ground for adjusting, and suddenly it wouldn't start.

I took out the throttle barrel and exposed the 2 holes on the bottom of cylindrical holes for the barrel, then crank the engine, fuel spill out from one of the 2 holes. I then poked the 2 holes on the throttle barrel with needle, they are not blocked. Tank is holding pressure as I can hear the hissing when disconnecting the engine side check valve tube.

But there is no fuel reaching the glow plug...........plug is dry after cranking.

What is the possible cause that fuel can not reach the glow plug from throttle barrel ? Examined the HS needle , it is OK.

I use Cool Power 15%, OS#8 plug (medium hot). HS needle at 1.5 turns. Regulator screw flush with casting (set by YS Parts and Service)

Frankie <span class="info"> </span>

Fuel not reaching the plug is going to be a blockage more than likely, there is a new fuel filter between the tank and the engine on this 15 year old plane?

Lets start at the needle valve since it is the last stop before fuel hits the crankcase. If you take the HS needle out and prop the the engine though by hand a dozen or so time at full throttle (without the glow driver attached) does fuel come out of the HS needle opening? If not it is not getting that far and we work backwards into disassembling the regulator.

Thank you for your reply Petec,

This posting is part 2 of my nightmare with this engine.

Part 1 started at the beginning of this year when I took out my Dash45 with this YS45FR invert mounted with Hatori tune pipe. The ship had been sitting in the storage for over 15 years. Before storing, the ship was only flown for less than 1 hour (engine not broken in).

All the time since the beginning of this year, I had been religiously following the instruction sheet of YS, opening the HS 3 turns, only turned a few clicks at a time back and forth when adjusting. This is when the trouble starts. Engine either quits from low idle to mid range, or cannot transit from mid range to high end. Have tried turning the regulator screw until it opens only 1/8 turns, but still did not work. During these 8-9 months, I have been tearing down the regulator and carb at least 7-8 times to the bolt and nut level, but found nothing abnormal, Disappointed, I decided to send the engine to YS Parts and Service, hoping to get the answer as to why the engine quits.

After I got the engine back in October, Richard told me he replaced the 2 bearings which are rusty, the diaphragm and gaskets. But I know the rusty bearings are not the culprit. For the diaphragm, no chipping, no damage. And I made the gasket using gasket paper before sending the engine to Richard, and engine could also start. 

Here come the interesting part :- when I got the engine back, I also opened the HS needle 3 turns. Engine starts but keep on quitting during transition from mid range to high end. I phoned Richard. Among a few questions he asked me, he asked how many turns of HS needle, I told him 3. He of course said it is way too rich. So I immediately reduced to 1.5 turns and engine transition to high end has no problem.

BUT the third/fourth time when I started the engine after this, it won't start. And I never had  intention to return to 3 turns of HS needle. Instead , I post this thread and asked for help. Just before I typed this reply, I removed the HS needle, as you suggested and cranked the engine using starter, fuel did spill out, meaning no blockage. In fact, I did mention in my first posting that when I removed the throttle barrel, exposing the 2 small holes at the bottom of the cylindrical hole, fuel did squirt out when engine is cranked. That means no fuel blockage up to the HS needle. I then suddenly switched to the idea of TRYING 3 TURNS OF HS NEEDLE AGAIN, and engine started right away. I experiment with 1.5 turns again, it would not start.

IN summary, it is very confusing with the setting of the HS needle. Petec, with your vast experience on YS, can you shed some light on the HS needle setting ?

Thank you.