Jackshaft Speedster

[QUOTE="kdaddy1980]
maybe ill look into getting a reed valve for it instead. does anyone have any suggestions of where to get them and which ones are the good ones? and where can i find a iridium spark plug?[/QUOTE]
Arrow Motorized Cycles makes and sells the best Reed valve for these motors.

I think Sick Bike Parts had the iridium plug.

I think which reeds you go with matters the riding you do I do almost all city riding and the RSE is perfect. when I first got my RSE I did not port at all. but the low and mid range gained very noticeable power increase. The top end on the other hand I lost about 6 mph. when I did the jug port on that engine I lost some of the low and mid range power I had gained but not all and was able to cruise at 40 plus mph and the motor did not sound as loud at the higher rpms as it had before I got the reeds. if I was trying to get the top speeds that some people want I would go with the arrow reed kit since its designed more like the 2 stroke reed kits I rember on dirt bikes when I was growing up.

I agree. The arrow reeds would definitely be the way to go if ur going for a high rpm screamer. The RSE reeds are fine for the normal rpm range these motors opperate in & u wont loose any rpm using them. The torque increase is significant, around 30% in my estimation. Using an 8 speed cassette (shimano hyperglide), I was using 6th as top (b4 reeds) as to go higher meant loosing speed due to not enough torque. Wirh the RSE reeds & piston ported etc, I use the whole 8 gears no problem. U will need to seriously upjet ur carb if u add reeds & properly port for as ur motor will intake to the crankcase thru close to 180 degrees instead of the 60 degrees its intaking thru now, resulting in much reduced intake velocity. I suggest u read up on reeds a little to decide which type will suit ur application. I dont think its a matter of 1 type being better than the other, more that 1 type is designed for above the normal rpm range use where the other is designed for use in that normal rpm range. Both arrow & RSE types increase crankcase volume (decreased CC comp ratio), the arrow a good bit more than the RSE, (but this can be a good thing for really hi rpm to keep transfer exit velocity from becoming excessive). The arrow reeds have much greater flow capability (suits hi rpm) & stiffer metal reed petals, which again suit hi rpm (require more suction to open but resist flutter at hi rpm much better). The RSE reeds will flow adequate for normal rpm (especially if u open the intake port roof up to allow the upper petal to properly open). The increase crancase volume very little being an in port design & the reed petals are quite flexible fiberglass items that reqire little suction pressure to open but if taken to above the normal rpm range by too much would have the potential to flutter. So u have to decide wot u want from ur motor so as to know which type of reed setup will best serve ur purpose. Hope this all helps. Cheers

As I said when I put my RSE reeds on and had not ported the jug yet I lost a few mph in top speed but Im 260 plus and with the reeds only the bike could pull me on a slight incline with just a little feathering of the clutch.

The RSE reeds are very good for the normal rev range or a little above & if u do the nescessary portwork u'll get a decent torque increase (very noticeable, right thru the rev range). U'll have to do a little intake port work on the jug (cylinder), but most importantly, u'll need to cut a port in the intake side of the piston to allow it to intake thru 180 degrees which is the whole point of adding reeds. I gave all the lowdown of how I did this, with measurements etc in another thread a while back (I'll find & steer u 2).
I'm not familiar with the CNS carb but know a lot of people use it.
An upjet means going to a larger jet to richen up the mixture due to reduced intake velocity. To give u an idea, I use a VM16 Mikuni carb. The jets are sized in increments of 2.5, which I think is just a numbering system, not a measurement.
B4 the reeds I was using a #25 pilot jet & a #77.5 main jet. After adding the reeds & porting for, I needed to a #32.5 pilot jet & a #100 main jet to get the mixture right. Without the reeds & piston port the motor wouldnt run properly with this jetting, it would be f¤ck¤n miles too rich. I think reeds work well with a jackshaft as having gears negates the need for hi rpm. Torque increases are of more benefit to u. These motors are very poorly ported, but the ports are arranged to give power in the lo & mid range, which again suits a jackshaft/geared setup. Knowing how to properly port a motor to move power delivery to another rpm range really is a bit of a "black art". If u dont really know wot ur doing in this regard, maybe its better to leave the power band where it is & boost it with (A) a port match job. (B) a better intake manifold (straight), carb & aircleaner, & fuel petcock. (C) a tuneable expansion chamber. Dont underestimate one of these. SBP offer a good one that is well worth getting. (D) a hi comp head (with squish clearance properly set, 0.030"). Upgrade ur small end bearing to a better quality, 15mm wide one b4 u do this.
If u do these things (I would also recommend an adjustable CDI) & ur pipe is tuned to where u want it (mid range), & ur carb is properly tuned, u'll have a good performer & have learned a bit about working on, tuning etc ur motor. If u still want more torque, then add the reeds. Just my thoughts. Also, its a good idea to replace ALL fasteners with automotive grade ones, socket head types where applicable, especially the mounting ones (where the motor mounts to ur frame, tho the rear should already be done from ur jackshaft) & the head/cylinder studs & nuts (use flat washers). Hope this helps. Cheers
Edit:
See the thread "Reed Kit" in this section where I went thru the whole proceedure when I added the reeds, includung a descruption of all the modifications I did to fascilitate maximum intake duration, including measurements. I also go thru the upjet which was more than I anticipated. I first just added the reeds (without mods) which required a small downjet due to eliminating blowback & felt just a tad stronger,,,, and then had at it to do it properly. Hope this helps. Cheers

I run a Arrow block and RSE is too restrictive and design for a 50 cc engine