I am running a YS 63 on 20/20 fuel and have heard YS like higher rpms than normal 4-strokes. Any idea of the rpm reange I should be looking for?

mid nines

I have a new one (63FZ). Dave Shadel told me to prop it to turn between ten and eleven grand on the ground (after an hour or so of running), then back off a click or two (rich) on the big needle.

According to him, the 63 likes to turn up faster than most other four strokes; including the other YS's.

My 91FZ with an APC 16x6 is turning 8700 on the ground, and seems to be very happy; likewise a buddy's 91FZ. The thing you don't want to do is load the engine down too much; that causes overheating.

I was concerned that the 16x6 might be too much prop, but I'm running rich (distinct, but not heavy, smoke trail in the air) and there are no signs of overheating.

He was specific about this on the 63; too low an rpm is not good.

Steve

Here are a couple of different sources for recommended R.P.M. ranges for the YS-63.

http://www.ysperformance.com/prod63.htm

http://www.centralhobbies.com/Engines/YS63FZ.html

The engines do like the revs. I prop my YS-53 to turn around 10,500. I will be installing a 63 in a new plane shortly, and plan on doing the same with it.

Outstanding engines!

Hope this helps.

Rex Rutledge

I run my YS 63 with 12x7 and 12x8 around 11K with Magnum #1.
Tons of thrust to pull 6.4oz pattern plane out of hand vertically!!

91 and 120 stay under 9K.

Yep, the YS 63 likes high RPM. Mine happily spins a Graupner 12x7 at 11,200 rpm on Powermaster YS 20/20 fuel. I tried a 12x8 and a 13x7 prop, but the engine seemed to be bogging down too much. You are asking for trouble if you run your YS 63 in "mid nines".

I bet that 6.4oz plane does float around a lot? I suppose you do have a problem with the vertical because the slightest little updraft would take it out of sight?

Both my 53 and 63 turn in the mid 11's. the 53 has an 11x8 and the 63 is running a 12x8. The 53 is in its 4th plane! My 91's and 120's run in the 95-9800 range.
You should be propping the little ones to get 10-11.5k. Below that your just wasting your resource.
Good Luck!

I'm learnin, honest.

I tach my 63 to run around 10,500 off peak.
I just got mine back from shop. and I have it set at 10,400 with a 13x4WAPC it peaking in between 10,800-11,000RPM right now, and that only with 40oz of fuel thru it.

And they are pretty engines too !!!