RSE Reed Valve Kit Mini Review.

GoldenMotor.com
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The Mechanic

New Member
Oct 30, 2012
4
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On my bike
Hey Folks,

I'm new to the forum but have been lurking for a while.

Just wanted to post a mini review of the Rock Solid Engine's reed valve kit that I just purchased due to very positive reviews on this forum and elsewhere.

So I have a stock 66cc china 2 stroke running a 44t rear sprocket that I have re-jetted the carby, added a SBP HD air filter, port matched the intake and exhaust manifolds and increased the muffler flow just a little.

It runs really well for what it is and I ride to work each day and love it! There is one BIG hill on the way home that she struggles up but nothing a little pedaling wont fix!

I figured a bit more torque would be handy for the big hills and headwinds and the RSE reed kit has so many glowing reviews for the price I thought why not.

So the reed valve manifold shows up and first impression is WOW this is a very well thought out bit of gear! Super compact and nicely machined, the actual reeds are a thin and very flexible fiberglass seemingly perfect for the low RPM china 2 strokes.

I bolt them on right away with only a slight clearance issue with one of the cooling fins on the head, I then attached my trusty NT carby which fits but only just as it doesn't quite clear the clutch cable stay and the cable itself rubs slightly on the float bowl, No matter small problems to deal with later.

The tuning processes starts and I end up having to up jet from a .72 to a .76 to get the engine running the way it likes. I finally end up with a plug color I'm happy with and an engine that runs and idles smooth with clean throttle transitions.

I quickly realize that although I have a smooth nicely running engine that It is not making as much power as before and no matter how I tweak the carby settings It just is not quite as good as the stock set up.

It struggled to reach speeds that were once comfortable cruising speeds and up hill performance suffered significantly, It just seems like it caused a huge intake restriction and the poor little thing although running well was sadly asthmatic.

I had to go back to stock intake and previous jetting as I just don't think with stock porting that the reeds are an upgrade at all In fact a noticeable downgrade sadly.

I'm in no way disrespecting Rock Solid Engine's as the product is first rate and would recommend it to any one interested in dabbling with idea of converting their engine from piston port to reed valve induction.

I just feel that a lot of port and piston modification would be require just to get the engine back up to where it was with stock induction.

Disclaimer: This is all just my individual opinion on the subject I'm not trying to upset anybody I just wanted to share and inform people that a reed valve set-up (of any brand) is not just a quick bolt on torque boost it is not that simple.
 
mew905

mew905

New Member
Sep 24, 2012
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Moose Jaw
you're actually supposed to add boost ports to the piston to increase the intake draw to ~170 degrees instead of the usual ~60. Just drill holes (another member will likely give you better instructions but this is essentially what you do) or cut a hole in the piston on the intake side so the piston doesn't block the port anymore at bottom dead center. Before reeds, the motor closes the port using the piston then compresses it. With reeds, the piston draws air and compresses it throughout the whole cycle. Basically you're just letting it take bigger breaths. A couple holes drilled into the piston on the intake side should easily restore your power, but ask for advice, or wait for another member to come on and give you more advice.

Here's a good site to get you started. The boost port topic starts about half way down the page (you'll see a paint drawing of a piston with a bunch of circles on it)

http://www.dragonfly75.com/motorbike/reedvalve.html
 
darkhawk22

darkhawk22

New Member
Aug 17, 2010
733
8
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Acworth, GA
Thanks for the info. I was wondering how well the reed kit would work as a bolt and go option. If the piston "has" to be modified to take advantage of the benefit then RSE should include a proper piston replacement in the kit along with some instructions. Then it would be more of a complete bolt and go package. Just my 2 cents.
 
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dmb

Active Member
Dec 4, 2010
1,354
3
36
lakewood ca
905 is right. it is not a bolt on power item. Norm at VeniceMotorBikes does't have these on his page because they dont work on a stock motor. and they are advertised as bolt on power by the co. that makes them. anytime you up the performance of something you risk the chance of problems? but you knew that. anyhow do the mods and you should be happy. good luck dennis
 
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ivan H

Member
Oct 8, 2011
622
1
16
australia
Hi, like others have said, 2 c a real torque increase u need 2 port the piston & modify ur intake port & u can boost port. With RSE reeds u should open up the top of the intake port on the manifold side 2 allow upper reed clearance. I posted details of mods I did in another "reed" thread in this section. I'm really happy with results. Figure 20~30% torque increase. I'll find thread title & get back 2 u. Cheers
 
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ivan H

Member
Oct 8, 2011
622
1
16
australia
Hi The Mechanic, c thread "Reed Kit". I did the piston ports to Jag's measurements but instead of drilling holes I cut 2 ports, each 17mm high, 9mm wide & left 6mm between them. This matched up to the intake port width that had previously widened by 3mm. All the port mods were done with a drill & dremell with cutoff wheels & carbide cutters & calipers, so its pretty easy. Well worth it. U'll need a serious upjet when done. Cheers
 
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ivan H

Member
Oct 8, 2011
622
1
16
australia
Just 1 more thing (so u dont get confused). The "Boost" port is NOT in the piston. There r a couple of ways 2 boost port but the 1 refered 2 is cut in the cylinder wall from the top of the intake port to the height of the top of the transfers. Boost ports r additional transfer ports & can also b cut between the transfers & intake port, from the bottom of the cylinder 2 the transfer height. Cheers
 
T

The Mechanic

New Member
Oct 30, 2012
4
0
0
On my bike
Hey Guys,

There are users of the RSE reed kit online saying that its the best thing since sliced bread and will show improvements even on a stock ported engine.

The purpose of my mini review was to dispel this myth once and for all so that others have a good idea of what to expect when considering a reed valve conversion.

I have no interest in further modifying my engine just to make the reeds work. I'd rather be out riding than in the workshop!

My curiosity got the better of me and the kit was cheep so I went for it now its going on ebay.

Have fun.
 
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ivan H

Member
Oct 8, 2011
622
1
16
australia
Hi Pawnrae, if u can get them,,,,,, takes bugger all 2 do all the portwork,. I did it with a set of calipers, deill & dremell with cutting disk & carbide cutters, & I got a bigger torque gain from than probly I got from SBP chamber, RSE head, VM16 mikuni & my homemade CDI combined, or at least equal 2. Cheers
 
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Pawnrae

New Member
Jul 26, 2012
8
0
0
Calgary
curios about the homemade CDI, i find the ones i get from my local retailer are the worlds worst and the last jaguar CDI on one site is sold.
 
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ivan H

Member
Oct 8, 2011
622
1
16
australia
The Jag CDI is the KDX CDI circuit with a couple of component values changed 2 suit these, & the same circuit I use with a few values changed 2 suit my requirements. If u can read a schematic my hand drawn 1 in "modified CDI & CR80 coil" thread is the circuit but with 3 different resistor values & later posts tell wot 2 change 2 make it the sama as jags, or I could make u 1, but I'm in Oz. Cheers
 
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lucajo16

Member
Dec 12, 2013
100
2
16
cincinnati, ohio
Does anyone have a link to a thread where I can learn. I just got my rotary tool the other day and am looking to use it bad. I got 2 bikes. One is a restore JC Higgins I wanna use one on and the other is a wally world test bike.
 
Davezilla

Davezilla

New Member
Mar 15, 2014
2,705
10
0
San Antonio Texas
If you want to learn porting, these engines are great to practice on since the jugs are nice and cheap, and so are the pistons. Look up "port timing" and "piston ramping" and you should find several write ups on the subject.
Start out conservatively by first chamfering the port openings to eliminate the overhanging nikasil at teh intake, exhaust, and transfer openings in the cylinder, this is more for longevity and reliability than performance so learn it first... emery cloth strips, jeweler's files, and diamond burrs fro the dremel are your friend here... Use high rpm and a really light touch when using the diamond burrs and keep them lubed with cutting oil or even wd40 and these burrs will last a long time, running them dry or trying to push too hard on the work will ruin them quickly.

Once you get that done, another easy job is to remove about 5mm from the lower intake side of the piston skirt... It's tempting to open it up and match the intake port but this'll ruin the port timing, if you're using a reed valve you can open it all the way to match the port, but without a reed valve you'll kill your bottom end performance.

On the top of the piston, shave off about 1mm at the transfer and exhaust ports and ramp them smoothly to the center of the crown... going about 1mm down and tapering out 5 to 7mm toward the center is all you need here... More than 1mm deep and you'll run the top ring land too thin and can weaken it, as well as messing up the timing.

Slightly more advanced but still on the easy side is to make the intake and exhaust ports 1mm wider on each side keeping them as round as possible to prevent ring snagging.

Then try to clean out that casting line inside the top of the transfer openings, don't mess with the actual port size and shape, just clean out that casting for now....

Now you'll have a noticeable improvement in power....

There's a lot more you can do by changing the port timing, but that's more advanced, you'll need a few more tools like a degree wheel, a depth micrometer, and a dial indicator if you plan on getting it right without going too little or too far on each port... This is where most people screw up the first time around so read all you can about port timing and get the right tools before attempting... Harbor freight has most the stuff you'll need on the cheap, and they're plenty accurate enough too.
 
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