Finally decided to run-in the nice NIB YS .63 I picked up from the swapshop a few weeks back. Unboxed it, fitted the muffler and an APC 13x6 prop. Wups! no glowplug included - so I fitted a new OS F plug by hand. Grabbed my tooltray and off to the carport.

Engine mounted on the stand? check!
Fuel tank filled and secured? check!
Glow heat? check!
Starter? check!
Main needle 2.5 turns open? check!
Regulator set? check!

Let's roll!

... and it refused to run! It started and ran raggedly for a second or two then shut off HARD. Refused to do more than pop after that. I tweaked and tweaked until the starter batteries died... no soap.

Recharged the starter, tried again. Still the same behavior. I was starting to think I'd received a lemon engine... grr.

Defeated, I was turning the engine over slowly by hand and glaring at it when I noticed a slight audible 'hiss' when it turned through compression. A leaky check valve, perhaps?

Then I noticed the fuel bubbling aroung the glowplug. You jknow, the one I had hurriedly scewed in with my fingers an hour-and-a-half ago

Arghgghghg.

Pulled the plug, cleaned the seat, reinstalled. With a wrench this time.

VROOM! Fired right up.

I put three 8-oz tanks through it at low-to-mid throttle settings, running nice and rich. No flameouts until the tank was dry.
Fantastic

Tank #4. I fired up, ran it up to WOT and then ... I leaned the main needle a half-turn. The carport filled with nitro smoke, the mosquitos beat a hasty retreat , the RPMs climbed to a scary point.... I pulled the throttle back, richened the needle and ran out the rest of the tank.

Oh Yes. I'm going to be very happy with this motor

Yeah, the YS are pretty sweet. I have a half dozen of them and have always been happy.

Mark

i have a 63 in a GP cub....runs great. by the way ya said 2 1/2 turns on the needle...is it not 1 1/2 turns? -Tinman-

I just finished my 2 gallon of byron 20/20. Fuel in mine. Mine will tach a 13x6 APC at 11,400-11,500 peak. I back it down to 10,400 and fly it.

Right now I have a 14x4 zinger on it peaks out at 10,900 I fly it at 10,000. I could probably lean it out a little more. But I am scared it will blow up. I really love this motor.

I have it on a Morris Hobbies Top Cap Arf. total weight is 4.5lbs. performance is unbelievable. People think I have a Saito 91 on it. I tell them something bigger and better.........(long dramatic pause......) a YS 63. Then they responce NO CRAP, that small of a motor pulling a 4.5lb plane like that.... Most people don't belive me that is only a 63...

my 63 will out pull a saito 91 any day of the week.

Tinman - I was running it on the rich side as I'm still running it in. Actually now that I think about it I was at 2 1/4 turns of the main needle. The one time I leaned it by a half-turn, so 1 3/4 on that side.

I have four other YS .53s. One on a Somethin Extra, one on a Top Cap. I had one on a .40-sized ME-109, replaced with an OS .52. (too much power for the airframe. bwaaahaha.) The other two on the shelf waiting for someone to get off his arse and assemble some planes

The 53 and 63 are exceptions to the rule with 4 stroke rpm.

These 2 little engines love to run high rpm. 11-12k is a perfect range. My 53 has a 11/8 MAS turning 11,800. And my new 63 has a 12/8 MAS turning 11,400 but I'm still running it rich.
Depending on your application and prop size I feel you are running it too cool and rich if you are running in the 10k range.

I put a new .63 in a Great Planes Corsair that I bought almost ready to cover in March. I only had to adjust the high end needle and nothing else. It is a real powerhouse. Like a previous poster, I am always having to answer the question "what size engine is that". Mine has been flawless since it first fired up. I am using an APC 12X7 prop. I would estimate top speed to be 110 or so. In fact, when I pull the throttle down to half, the decrease in speed is hardly noticeable. Unlimited vertical performance from the instant the plane leaves the ground. It also forces me to use that right rudder, especially at takeoff and when doing touch and go's. Worth every cent of it's price.

i have a TF 60 size corsair waitin for a motor....wonder how the 63 would pull it...what is weight of the GP corsair ya have?
-Tinman-

I don't have anything to weigh it with accurately. If I had to guess, I would say 5.5 to 6lbs. The Great Planes Corsair is considerably smaller than the TF Gold Ed. Corsair. I have a buddy who has one and he uses an OS .91FX which is a great combination. Very fast (for a .60 size Warbird); guessing around 120 to 125. I can't remember for sure but I believe he is using a 14X10 prop. I would have thought that was too much prop but it seems to like it.