RSE Reed Valve Kit Mini Review.

[Slogger]

Thanks for the heads up, Mechanic. Some guys will buy a new part, bolt it on then tout it as a great upgrade regardless of its actual performance.
Reeds would make a lot more power, but I see now they need some grinding and shaping of the ports and whatnot. My little CG is running better each ride now, almost broken in. 10 hours of riding time now..
I don't want to take it all apart and experiment with it, possibly trashing the barrel or piston, leaving me bumbling around (for ten hours) on a new barrel and slug, arrrgh.
THANKS!

 

[Davezilla]

Agreed, the RSE reed does claim to be a "bolt on and go" mod but there's a second side to this story, it does work and will enhance the low end performance, but with these engine's short port durations the additional power you get down low comes at a cost of power up higher in the rpm scale where most people want more power... so they can go faster. You'll accelerate a little better with the reed installed, but without doing the extra porting and cutting windows in your piston skirt or even adding a boost port, the bike will most likely lose some top speed.

 

[exokinetic]

The window in the piston is the most important part, if there was no window in the piston (or cut-away from the piston skirt) then you are not increasing your intake timing duration, witch is -among other things- what converting to a reed valve would allow you too do.

Alternatively, if a "boost port" is cut from the bottom of the cylinder bore (underneath the intake port) up through the intake port, and out the top, to the same height as the transfer ports, the piston modification is not required, but will still provide an improvement in overall flow, and performance.

The "boost port" also known as -in our case- the third transfer port (cut from the intake port, up, to the height of the transfer ports) increases the performance gained by creating another path for this extra intake charge (if you do indeed increase the intake timing) to get into the cylinder.


Reed Valve conversion without Piston Window or Boost Port = Meh

Reed Valve conversion with Piston Window and no Boost Port = Improved low end power, possible loss in top end (depending on window size/shape)

Reed valve conversion with Piston Window and Boost Port = Even more improved low end power, with more top end power too.


I run the RSE Reed Valve with this modification to the stock piston:

If you have any other question don't hesitate to PM me.