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Two stroke advice needed
westf27 - 18/2/13 at 05:09 PM

got a little 50cc honda two stroke in a moped which has a reed valve fitted to the induction manifold.
a small piece of crud had jammed the valve open which i have since reoved.The question is should the reed be just closed,under slight pressure closed or just open.


Canada EH! - 18/2/13 at 05:27 PM

The reed acts the same as an intake valve in a 4 stroke, should be closed when engine not running, incoming air on intake stroke pushes it open, the reed then closes for compression and exhaust.


doddy - 18/2/13 at 05:31 PM

if its open a little you can turn them around to get a better seal


MikeRJ - 18/2/13 at 06:09 PM

The reeds should be fully closed at rest. If they aren't then they have probably been bent by the crud it's inhaled.


wombat - 18/2/13 at 06:23 PM

+1 Turn them over.


RIE - 18/2/13 at 07:50 PM

quote:
Originally posted by Canada EH!
The reed acts the same as an intake valve in a 4 stroke, should be closed when engine not running, incoming air on intake stroke pushes it open, the reed then closes for compression and exhaust.


It would be open during compression/exhaust, and closed during transfer (cylinder intake) Air/fuel charge is in the crankcase, piston descends, pressure in the crankcase closes the reed valve and forces the charge through the transfer port into the cylinder.