Dauntae,


The newer Webra .61 has the muffler bolt holes drilled and tapped in the exhaust stack, at an identical configuration to MVVS .61-.91 and to OS.61FSR (and their clones).

Due to cost and quality issues, as well as being able to select between five (5) different muffler options, a significant number of OS.61FSR and Webra .61 Speed engine owners selected to get an MVVS muffler/tuned silencer/pipe from me.

The older engines, like your own, have no bolt-holes, so the 'change nothing' option is to get some kind of strap-on muffler, or header...
But if you are, or you know a reasonable machinist, the 4 mm bolt holes must be drilled and tapped 34 mm apart (center-to-center - use a bottoming tap and don't drill as deep as the cylinder sleeve...), for the standard MVVS exhaust (or that from the OEM) to fit unaltered. If you use Imperial fasteners(4-40, 6-32...), you can tap the holes any reasonable size.

E-mail me if you're interested.