Matt , the Aprilia ended up with a 120 rod om 54.4 stroke.
Honda had a short 105 for ever , but finally saw some light in the last Aoyama RS250 that had 109.
In karting its still a matter of conjecture , but the shortest is 105 , the longest 115.
TM have 109.8 due to a CNC error 20 years ago.
Depends upon the intake system somewhat in that any RV loves a big case , so long rods make this easy to achieve.
Reeds seem to have a bottom limit of diminishing returns at about 1.3 ratio - any bigger case and you have to use excessively thin petals to get the case Helmholtz
and the reed first mode frequency correct.
Then the reeds start going spastic and you loose any extra power gained from the bigger case reservoir volume.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
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