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Reed block sizes

Posted: Sat Nov 26, 2016 8:02 am
by mboddy
Yamaha TZR250 2XT and 3MA-1 had large 8 petal reed blocks. Then 3MA had same size reed blocks with 6 petal reeds.
Am I correct that TZR250 3XV and TZ 4DP and on all used smaller 6 petal reeds and blocks the same size as each other?
Am I correct that these were the same size as the Honda NSR250, RS125 and RS250?
So is this the optimum size for power for a 125cc cylinder?
Smaller blocks with stuffers are better than large blocks?

Lozza - please see PM

Re: Reed block sizes

Posted: Wed Nov 30, 2016 11:00 pm
by 2TInstitute
Reed cage design is like most things 2 stroke counter intuitive , you would think a larger cage would make more top end but smaller cages seem to do the job. Given that a CR 125 is the same cage as a RS 125/250 and they are in use up until the A kit level (cage is smaller) but make 10hp more size isn't the issue.
Today lots of work going into the stuffer design with vertical and horizontal aerofoil shaped dividers to guide the air to the tip of the reed.

Replied to your PM Mark.