Do I NEED a windowed piston in order to use a reed valve?

[NukeSnicks]

So Ive been trying to get this darn bike started for a month now and nothing is wrong any of the parts from what I can tell. I got the OKO Dio Reed Valve kit and it didn’t come with a windowed piston and someone said you need a windowed piston to use reed valves. Is this the case? Thanks in advance!

 

[xspade17x]

Yes the windowed piston makes an Incredible difference you also need a third transfer port. I went thru this with my yd100 with a reed valve

 

[Jug]

Yes the windowed piston makes an Incredible difference you also need a third transfer port. I went thru this with my yd100 with a reed valve

You don't need a third transfer with windowed piston
You only need one

 

[Sumsloppymeet]

Depends on how much you're ported out actually the windowed piston sized right will actually give you a slight increase in power when used together just keep the window looking like this and you should get more out of it assuming you're already using a tuned expansion chamber in this setup of course

 

[FNTPuck]

With a reed you need to have either a windowed piston or a third transfer.

 

[xspade17x]

I have both and I noticed a substantial difference. First I did the windowed piston rode it awhile then added the third transfer port and from my experience you get better all around low mid and high range performance when you have BOTH.

 

[Street Ryderz]

Reed or no reed you need to know how to setup,jet and tune that carb,didn't you say in another thread that you went back to stock intake and piston?

 

[Jug]

I have a third transfer and window piston.
I was just saying that as beginners think reeds are the biggest deal and you need the big boi ZeDaMoToRsPoRtS motor for it.


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[YetiWoodz]

If I am correct, in an engine without a reed valve, the piston acts as a "valve" by blocking the intake port as its moving up and down the cylinder and it controls the timing. An engine with a reed valve no longer needs the piston to act as a valve and the reed valve now needs to control the timing instead of the piston in order to maximize performance. So a windowed piston allows the reed valve to control the timing because the piston now isn't blocking as much of the port because of its windows that allow the fuel mixture to enter through.

 

[Street Ryderz]

If I am correct, in an engine without a reed valve, the piston acts as a "valve" by blocking the intake port as its moving up and down the cylinder and it controls the timing. An engine with a reed valve no longer needs the piston to act as a valve and the reed valve now needs to control the timing instead of the piston in order to maximize performance. So a windowed piston allows the reed valve to control the timing because the piston now isn't blocking as much of the port because of its windows that allow the fuel mixture to enter through.

Basically yes the reed open and closes with the change of pressures and the window in the piston just allows for a longer intake duration.