ORIGINAL: riot3d
The Akiba Beat-On is a good design.
If you're using the 4S YS 63, you don't need a tuned pipe. Either a regular cigar shape muffler, or, a Hatori type short muffler will do. Just pay attention to the final weight, it may be slightly nose heavy.
However, with the Beat-On being an order design, it probably has a pipe tunnel. Therefore, you can use an older style Hatori flexible header connecting to a Macs long silencer, that will work great. Be sure to soft mount both your header & pipe. Otherwise, the header will break quite easily.
Adrian
I looked at the engine mount and I will need to move the YS63 back because of the prop hub position. If you think it would be okay then I will go ahead with that. Do you have a recommended source for the Hatori flexible header and the silencer? I apologize for asking these basic questions, but what do I need to "soft" mount the header and pipe? Thanks.