Originally Posted by
speedracerntrixie
Yes, add the nipple on the muffler for more consistent runs. The window I beleive was to drain exhaust residue from the muffler. That engine was made when fuels with higher levels of castor oil was more the norm due to the metals chosen for the piston and liner. Castor is a heavier more viscous oil then the modern synthetics and tended to pool somewhat in the mufflers.
Actually the plate on the early Enya mufflers was to allow exhausting priming for starting-and featured on all the Enya mufflers of the era other than the 049/06/08/10 unit. Fuji mufflers were similar. Likewise OS mufflers of the later 60s had a small hole for priming in the muffler casing directly opposite the exhaust opening...a practice that was eventually dispensed with...
ChrisM
'ffkiwi'