Reed Valves

Moisstink · Jan 10, 2015

I just installed this reed valve kit on my engine and it seems to help a little. The reason I did this was for the upgrade and thought it may help the bike run a little smoother. After the purchase for 40.00 shipped I ran across a 160.00 version that stated "There are some cheap, Chinese copies being sold on eBay - STAY AWAY!!! These are knock offs of this design in looks only, but the reeds themselves will break apart, get sucked into your engine and destroy it." Has any one really had this kind of experience or is this company just trying to justify 120.00 more for their kit. I mean their is not much to the kit and it looks well built. I do know these reeds are listed as fiberglass. If anyone has any experience with this kit let me know. Thanks

Animatronicus · Jan 10, 2015

I saw the same thing on ebay, and I too am wondering the exact same thing. I have seen the reed's made out of carbon fiber. Im wondering if its possible to DIY one.

Moisstink · Jan 10, 2015

I took my ride out today and tested the reed valve kit and it does not seem to do a whole lot. I do not have the engine ported so I have read this is one thing that will help the benefits of the reed kit as well. Low end seems better but I have an older 60 - 80 cc with an expansion muffler and still am maxing out around 25 mph. It is still kinda in the break in stage. Any info on people running the reed set up let me know what your experience has been. I think the 160 dollar reed kit is a fiberglass reed as well.

Animatronicus · Jan 10, 2015

You should be going way faster than 25 with those mods. How many tanks of gas have you put through it?

Moisstink · Jan 10, 2015

I am still breaking it in so I am not doing any wide open for any real stretch but I would say I have gone through maybe a 3/4 gallon of gas. It has been a while since I have done the break in period. I thought it was a gallon or two.

Theon · Jan 10, 2015

Honestly, That is a DLE 30 Reed, from a 30cc model aircraft motor. I would be replacing the reeds with something better. From Treatland, you can buy a sheet of Polini green reed valve. Which is what I recommend. But I'm sure another carbon reed may be cut to fit?
There is a larger reed valve kit made for the wide inlet barrel, which employs a DLE 55 reed, which is better sized for a 66cc motor than the DLE30.
To get the most from the reed, you will need to increase your inlet open time, and with such a small reed, I would be aiming for inlet open for 180 deg (reed closed for other 180), which will likely mean drilling holes in the piston.
To get the very most, Boost ports and good TUNED pipe.
Hope this helps.

Theon · Jan 10, 2015

Most report using the smaller (DLE30) reed will decrease top speed due to increased inlet restriction, without increasing inlet timing, this can be a significant 'step backwards'.

Moisstink · Jan 11, 2015

Thanks for the info Theon. I have read a lot of different information on these. Here is a photo of the other kit that people swear by which is the "Motorized Bicycle RSE Reed Valve - for 32mm Studs THE ORIGINAL!" 160.00 on fleabay. Just trying to see if anyone else has used either one and I guess what their impression is on them. First photo is the RSE and second the cheaper version I picked up. Anyone that has used these let me know what you think. It looks like they both use fiberglass reeds. Hopefully it does help out on top end as well. Hey as a heads up I just read this on piston bikes info on reed valves that "Don’t worry if any of the petals break and go into the engine, we have purposely designed them to be made out of fibreglass & it will not damage any internals of the engine, they are available as a spare part if ever needed." So that question is answered. Once again anyone using these let me know what you think.

Davezilla · Jan 12, 2015

Like Theon said, these reeds are off a DLE 30cc RC model aircraft engine and they cost about $8 to $15 brand new, the reed block and adapters in the kit are what make these work on these engines. The fiberglass reeds will last a really long time and if they do break, they'll get ate up by the engine before any damage to the engine could occur. That's the beauty of the fiberglass or carbon fiber reeds.
I know RSE does make another reed valve kit with a slightly larger reed I think from an 80cc DLE RC plane engine, not all sites sell this reed and they do cost more, but for these kits, the genuine and the knock offs are about the same, and the reeds can be replaced on the cheap with genuine DLE reeds if they do wear out.

As far as top end performance with this reed, it's a fairly small reed but it can perform if you do the piston mod so you can get full intake duration, they'll work bolt on and go, but they really need the piston skirt mod (just a window in the skirt) for better top end and to take full advantage of the performance gain, this is easy to do with a drill and a dremel.

cannonball2 · Jan 12, 2015

I read the same thing about the knock off, so bought the RSE for $59 shipped. Nicely made piece. I have not done the piston/porting mod yet. My goal was a smooth running torquey engine with no desire to mod for top end. Mine is far from broken in also. Running the reeds dead stock shows an improved idle, with good bottom end and no 4 stroking. I removed the reeds and ran it stock and it 4 strokes in the lower and upper throttle ranges. Its still too early in the engines break in to make judgments, but the reeds do seem to enhance low to mid throttle. Will do the necessary mods after break in.

YesImLDS · Jan 12, 2015

When running reeds you have change your port timing to get the actual benefit of the reeds themselves or as far as I have read. That's why people cut big windows in their pistons when installing reeds like Dave has mentioned above.

Moisstink · Jan 14, 2015

Thanks for the info. I appreciate it.

Moisstink · Jan 14, 2015

Davezilla said:
Like Theon said, these reeds are off a DLE 30cc RC model aircraft engine and they cost about $8 to $15 brand new, the reed block and adapters in the kit are what make these work on these engines. The fiberglass reeds will last a really long time and if they do break, they'll get ate up by the engine before any damage to the engine could occur. That's the beauty of the fiberglass or carbon fiber reeds.
I know RSE does make another reed valve kit with a slightly larger reed I think from an 80cc DLE RC plane engine, not all sites sell this reed and they do cost more, but for these kits, the genuine and the knock offs are about the same, and the reeds can be replaced on the cheap with genuine DLE reeds if they do wear out.

As far as top end performance with this reed, it's a fairly small reed but it can perform if you do the piston mod so you can get full intake duration, they'll work bolt on and go, but they really need the piston skirt mod (just a window in the skirt) for better top end and to take full advantage of the performance gain, this is easy to do with a drill and a dremel.

I have found links to porting but I am not sure if I have anything specific to doing a Piston skirt mod. Does anyone know of a link for more info on it, or how to do it correctly to work specifically with the reed kit. I have jets in the mail to dial that in this weekend. Would like to take care of both and see if I can get into the mid 30 mph range at least. I have researched these and have tried every upgrade or mod and still breaking in the engine but not passing mid 20 mph. Thanks again everyone!

YesImLDS · Jan 14, 2015

You don't want to do the piston skirt mod with reeds. You want some holes on the intake side of the piston. Just did a quick search and found a picture on this page part the way down. Couldn't find what I wanted to but this should explain it.
http://motorbicycling.com/showthread.php?t=53892&page=2
This changes your port timing so you are getting more air fuel mixture intake the crankcase with the reeds.

You will want to port match your intake and exhaust to match the jug itself like this

That will just help everything flow properly. Hopefully this helps. Anymore questions don't be afraid to ask! Plenty of knowledgeable people here who know much more than I!

Theon · Jan 15, 2015

That was the pic I was thinking of, don't know how to repost pics, but that link works.

YesImLDS · Jan 15, 2015

Some people literally take a dremel and cut a big rectangle and that works as well. It doesn't have to be drilled holes by any means. I'd do the rectangle if I had reeds

frank66 · Jan 15, 2015

edited. edited.edited

frank66 · Jan 15, 2015

higher if you want but the parts make it difficult. when the carb signal gets seperated /chopped- jetting gets harder an harder. if the carb signal/vacuum is even- jetting is easy.

frank66 · Jan 15, 2015

3 ways to do it.
- two holes side by side
-rectangle cutout upwards from bottom of skirt.
-single hole/ rectangle etc

becuase the piston is so tall/ byfar the easiest is a single hole.

rectangle hole is going to be fantastic like pictured below. two holes side by side great..... single hole is very easy.

YesImLDS · Jan 15, 2015

While in comparison a hole would be easier, but what is fifteen minutes with a dremel? You want maximum port timing with reed valves, or so I have read because I am not an expert what-so-ever. A rectangle would optimize your port timing so you can get the maximum amount of fuel and air mix in there. Something like this

Reed Valves

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