Hopefully this question hasn't been asked TOO many times, but I was hoping you guys could clear this up for me.

I know that for most 4 strokes to be run inverted successfully, the centerline of the fuel tank should be at level or lower than the carb of the engine.

However, I've also heard that since YS engines have a built-in pump, they don't have this requirement. Is this true? I'm sort of deciding between a YS63S and a Saito 62, and this might be a decision-maker. Thanks.

This does not matter when it comes to YS engines. They can be run at any attitude, from any angle and as far from the fuel tank as needed You will still need to be vigilant when setting the low-end but in my opinion the YS is the pinnacle of 4 strokes.

I have owned the YS-63 and it was a wonderful engine! Saito's are awesome but I'd take the YS-63 over a Saito-72 or 82 any day

YS engines almost sound too good to be true on paper. More power, no problems running inverted, and only about 20% more expensive than OS or Saito, yet they have a lot of detractors. I've heard YS supporters say that the hype about difficulty tuning YS engines is generated by simple lack of following instructions, but there can't be THAT many people who have trouble reading, can there? What makes these engines so hard for so many people?

Because people do not want to change how they tune an engine. They think that all engines are the same.[X(] The YS is a very easy engine to tune if you read the directions, and not listen to every guru at the field that has no idea what they are talking about when it comes to a YS unless they fly one.

Correct. The regulator will prevent fuel from entering the carb even if the tank is several feet above the carb. Yes, YS engines are pretty easy to tune if you use your brain. I don't even bother with the other brands anymore (maybe with the exception of the new OS supercharged FS-200).

Sounds good. Are there any 90 degree adapters or flex pipes available to avoid the muffler sticking out of the side of the cowling? I know the Saito 62 has these accessories available; hopefully the YS does as well.

These two engines can't fairly be compared as far as performance goes. You may want to compare to the Saito 72/82.
It's all fun!

I have a YS .63 in a GP Reactor and love it. I used a 90-degree adapter from Performance Specialties and it has been problem free. Here are a couple of pics.









OK...that's more than a couple. But it shows how the muffler is easily contained within the cowl. If only I were better at cutting the openings to match the engine. []

E

Central Hobbies also sells headers and mufflers for the YS-63 that don't stick out.

JustErik, that looks awesome. Unfortunately, Performance Spec now only seems to sell a different kind of elbow for the YS (black in color) that only connects to their aftermarket muffler and not the stock muffler that comes with the engine. Their mufflers are elso cigar-shaped (ie, no bend), so the orientation is a litte different. I wonder if that means I'll need the 75 degree adapter rather than the 90 degree one.

Richard, do you mind sharing what engine mount you used for the YS63S in your Kyosho Zero? Looks good. Thanks!

http://www.warbirdobsession.com/kyosho_zero/index.html

I used a 2-piece aluminum engine mount. I believe they are Magnum.

Does Magnum make mounts? In general, do YS engines prefer aluminum mounts (with/without rubber grommets) or glass-filled nylon ones? Does it matter if it's the base YS63 vs. the "S" model? I remember reading something about how the non-S model can warp it's crankcase with certain mounts.

Here you go: [link]http://www.hobbypeople.net/gallery/279950.asp[/link]

It doesn't matter what mounts. If the plane requires nose weight, then I use the heavier aluminum mounts. If not, then I use nylon mounts.

The YS63 uses the same header thread as the OS70 and 91 Surpass. Go to the Tower website and look up OS flexible headers, mufflers, accessories etc and they will fit the 63. The Performance Specialties stuff works well too.