Stock CDI: Seeking thoughts on replacement

[245luigi]

I have not found the CDI to be restricted on mine. What made you think yours is?

[StevieLike]

Mine definitely was restricted. It didn't run over 35 mph and after replacing it, it did. Anyway you can just cut the pink cable on a restricted CDI (Kymco Like) and it should work unrestricted but I heard the Naraku has a different ignition curve...I am pretty happy

[245luigi]

Interesting...Did you cut your pink cable or just go with the Naraku CDI?

[Vintage MX]

I put a Narraku unrestricted CDI on my 2012 Like 50 2 stroke.  Racing Planet has them for $99 and says they are specifically for the 2 stroke.  My bike had an unrestricted variator bushing, plus 1000 rpm spring, Technigas Silent Pro exhaust and correct jetting.  The "unrestricted" CDI made no discernable difference in speed, top rpm or acceleration.  When I complained to Racing Planet, they told me that the bike needed to have more modifications (more radical exhaust, bigger carb, etc.) to receive any benefit from the Narraku CDI.  They also claimed to have a dyno chart to prove it.  Unless your bike is highly modified, I would not bother.  But if you still think you need one, I'll sell you mine for $75 plus postage :-).  It only has two hours on it!  Be safe out there.

[245luigi]

Vintage MX, thanks for the offer. After some more research I may take you up on it. Although I swear someone on the forum confirmed with Kymco Corporate that the Like50 CDI had no restriction.

[zombie]

I think you are correct 245. There is no real "rev limiter" but there is a restrictive Ign Curve. It starts at 18*BTDC, and straight lines to 0* @ 8,000 rpm.
That is why RP claims the bigger Mods work, and not the factory set up. In essence you are forcing the revs due to port timing, and pipe efficiency.

The EASY cure is an HPI programable Ign. but is costs as much as most scooters are worth. Approx. 600.00USD. On the flip side you will spend that much on parts to force the rpm.
It's a coin toss in my opinion. Soooo I did both.

[245luigi]

Zombie, any predictions as to what the Narkus Ign Curve looks like?

[zombie]

I'm pretty sure either Josh (Aeromyet) or me posted it on the forum once. I think it was in an S9 thread but it was the same CDI.
I believe it was 18* initial, peaking around 23* @ 6-7k rpm, and sloping off to 3* at 12k.
I remember it because I modeled one of my first HPI curves after it. It is a good curve for City type riding or circuit track with lots of stop/go. Good torque up thru mid range. Not too good for sustained WOT/drag bikes  tho. The advance falls off as the pipe starts to hit kinda flattening them both abit. Still better than OEM tho.

You could set up a low rpm pipe/jug combo, and really nail the cdi's curve. Something that makes power between 7-10k Then the dropping curve will help to over rev safely.

Scooter Parts | Racing Planet USA | CDI unit Naraku racing for Kymco LHB3 | Electric Parts | Like 50 2T KE10AA | Kymco (Kwang Yang)
http://www.racingplanetusa.com/unit-naraku-racing-kymco-lhb3-p-135311-1.html?cPath=2_26378_26390&sessID=83bc70b7a904a82977c628e063cdceaf#.U2ARt-Z_7IY

I think they can verify the curve at RP. If not an email to Naraku
Home | NARAKU performance
http://www.naraku.com.tw/
They don't make most of their stuff. The factory that makes the CDI is the same one that makes the Kymco OEM CDI. I forget the company but it is in alot of my earliest posts here. Try searching ZX 50 CDI / Zombie
It would be some of my first 6 months or so posting.
That factory is where I got most of my cdi "education". Getting someone that speaks English is the hard part. Just keep saying Kymco CDI. They will figure it out.

[245luigi]

BAhahaha thanks for the info. Im on a Malossi Sport BBK with the Next R exhaust. Most of my power is between 7500 and 8500 rpm. Sounds appealing...

[zombie]

I agree! Perfect street kit. I had the same type set on the Dio/ZX engine. and it ran 50-55 all day for 2-3 years.
In fact I wore the bore out. Pistons started breaking skirts at something around 3 years.
I would run that set up again.

[245luigi]

I just received the CDI from Vintage. Ill be sure to update ya'll on my opinions of it.

[zombie]

I just saw your Sig. says 10gr rollers... Any reason they are that heavy?
I would think 5ish would be normal.

[245luigi]

Im trying to lower the rpm. Before (50cc) i was going x rpm at y speed, with the BBK at y speed, my rpms were way higher. I put higher rollers so my rpms would be lower. I have the upgear kit but have not installed it yet.

[zombie]

Makers sense to me!!! I ran 8's in the zx at 6:1 rear gears. It's running 4.5's now at 8:1 gears.

The 8's were for the one mile MPH things I was doing, and it was 82MPH @ 12k rpm.
The 4.5's are doing 65MPH @ 12k rpm on the street, and it tops out at 69-70ish @ 14k

[245luigi]

Very cool. So basically im using these weights to "restrict" the bike. Im not trying to blow the thing up....just yet! Any idea on mph increase I can expect with the gears? Just curious.