I am very familiar with the Y.S. 45 side exhaust engine. I have run them with tuned pipes and they are a rocket. I was wondering if anybody has tried running a Mac's header and a MCM. I want the midrange throttle response that you don't get with a tuned pipe.
I was thinking that if this worked out it would be a good combination on an Extreme 330 ARF - Goldberg.

Use the YS 45 with a tuned pipe and a 12 1/4 by 3 3/4 prop with 15% nitro and you'll be able to hover at about half throttle. try it its a really good combo.

Chris

About how much power does a YS 45 have? What RPMS do you get? I was thinking of using an Irvine 53, because it is cheap, but if I can find the price of the 45, I might change my mind.....

You would probably be better off with the Irvine 53. I am wondering about the Y.S. because I can get a used one at a great price. I remember that on a plane I had years ago I was getting 14,000 rpm with a Y.S. 45 with a Mac's header and muffled tuned pipe on a 11-6 APC prop. A new Y.S. 45 costs about $160. and you don't get a muffler with them.

Thank you for your info. What I want to know is how the Y.S. 45 runs with a Mac's header and "MOUSE CAN MUFFLER". I am familiar with the engine and a Mac's header and TUNED PIPE.

I can't answer the exact question that you are asking because I don't have a YS 45 but I don't see why a MCM wouldn't work great on one.....I just got done putting a MCM on an OS .46fx on my CG EXT 330 and it is great and really brought the engine to life....I was using a tower muffler but it didn't compare to the performance that I am getting with the MCM.....I haven't tached it yet but with a 12.25x3.75 APC it hovers at barely over 1/4 throttle and pulls out of hover like a rocket....I think the Mousse can would work great with a YS the only thing I would say is that you may have to move your battery back a little bit if you plan on putting this on the CG Extreme because I think the YS is a little heavier than an OS.....just my .02 cents