lil3incher
Member
Some of you might think sounds silly, but I was wondering What do Reed valves do and Does my 98 VMax SX 700 already have them, and if not what advantages will they give me? Thanks
sleddineinar
VIP Member
Yes, it has reed valves. Reeds maintain the the case pressure.
SX600abuser
Member
When a piston moves down in the cylinder it is decompressing the air in the combustion chamber, however it is compressing the air in the crankcase side. The air doesn't compress very long before the piston clears a series of ports, opening air flow from the crankcase to the combustion chamber, creating air/fuel flow for the next combustion event.
Old 2 strokes without reed valves relied on the piston to also block and unblock the intake track from the carburetor so the air/fuel mixture wouldn't push back out of the carbs. Reeds allow for the intake track to be moved to a more optimum location in the crankcase (essentially a 1 way valve, lets everything into the engine and keeps it from blowing back out).
Old 2 strokes without reed valves relied on the piston to also block and unblock the intake track from the carburetor so the air/fuel mixture wouldn't push back out of the carbs. Reeds allow for the intake track to be moved to a more optimum location in the crankcase (essentially a 1 way valve, lets everything into the engine and keeps it from blowing back out).