Kymco ZX50

[zombie]

Go colder, and richer. The needle I sent is a thiner quicker taper than the part # you posted so it may help . I would still go another step richer. That plug is too dry, meaning the comb. temp. is too hi. Colder/richer/thinner needle. It will have to be done again when you put the pie on, but by then you will be an expert at carb tuning!

[sidthesloth]

Cheers mate, I dont know about being an expert but sure am learning.

[sidthesloth]

G'Day zombie, I now have an exhaust on the way, it is from the manufacturer of the cylinder kit so it should match pretty well. Earlier you asked about info on the cylinder, well apparently it produces 13 hp. @ 8,800 rpm. They do also sell carbs. for this set up, but I will have to wait until I can afford it. Patience. Going through some old posts it seems the C.D.I., voltage regulator and coil are weak links. You had found  a company that will program them to your desired settings, would they be able to build in a rev. limiter at a given point so as to protect the engine from self destruction, yet still achieving a resonable power output?
Cheers
Rob.

[zombie]

From everything I have read on the zx, It has one of the strongest crank set ups you can get. The rev limit can be set at any point you desire, but WHY? Your set up will most likely spin up to 11'000 and still be strong so maybe set a limit around 12'000-12'500. If you go thru Suitai, I would suggest standard timing, and that 12ish # for the limit. It,s going to be a steep learning curve for your kit, so I would think to wait on the cdi until the carb is set up. Your de-restricted cdi will do the same as their new one it just may not last as long. I was eating them up, until I bought the last one. The way It was explained to me is the circuit will overheat with high rpm's, and that causes the failure. With your stock carb. I don't think you will be spinning over 7,000-8,000 rpms. w/ the larger carb it is a whole new tuning game. Do you have a make or mm size for the carb they suggest? You want to be sure it is a quality carb. or the tunning will be that much harder. I prefer anything w/ a turn off cap on top. Mine has a bolt on, and has ALWAYS been trouble. I wound up making an epoxy glass cap the seals much better, and is much more stable.

[sidthesloth]

G'Day zombie, they offer carbs in 19, 24, 28,30mm. the image looks like a screw on cap. with the cdi, the voltage regulator should prevent that, I would have thought.

[Shaka]

I have been running my stock de-restricted since I bought the scoot almost 2 yrs and 12,000kms ago.  I am on my 3rd voltage regulator.  Still the original coil.  I don't think there is any need to put a rev limit on the cdi.  They are factory restricted to meet local laws for import, not to protect the engine.  Like Zombie said the bottom can hold the extra torque and high rpms.  The new cylinder should be designed for it as well.  I'm using a 19mm Arreche carb on my 70cc, so I would think a 24mm would work well with your set-up. 

[sidthesloth]

Cheers shaka, I am in new territory, way out of my depth, kind of exciting. I was wrong with the carb, they are not a screw top, I think they are a flat slide. So do you reckon it is worth getting a spare voltage regulator?

[Shaka]

You may want to get a spare one if it is hard to get parts where you are.  They are relatively inexpensive as well.  I think mine cost about $30-$35 from my local dealer.  You can get them much cheaper online though.  Do you know what manufacturer those carbs are?   My guess is that only the larger sized ones are flat slide.  I don't that I've seen a flat slide smaller than about a 28mm.  The screw top really does make tuning easier, as well as a removable cap in the bottom of the bowl to access the main jet.

[sidthesloth]

I dont know the company name but they trade as autotech355 on ebay motors.com. if you do a search for honda dio carb that will come up. yeah I think online is the only way to go nowadays.

[zombie]

The cdi is fired by AC voltage on the zx/ so the regulator has no effect on protection. all the reg does is fire the lights/horn, and charge the battery. I trust what I was told it is a rpm thing that causes the cdi failure. If you de-restrict and run a high reving engine it will fail. That happens because we are shorting a circuit that limits rpm's not completing an open circuit. Now the bad news. the 24/28 will both do the trick. They both also need larger reeds, and intake manifold. You can run a rubber adapter for the carb., and a good set of reeds. that will require jetting the new carb. to your current set up, then re-jetting as you swap out parts. That,s why I knew you would be an expert jetter. Practice makes perfect Bro! I'll check out the carbs tonight. I,d like to see what else they have!

[sidthesloth]

Thanks zombie, the carbs come as a set with manifold and reeds as well as air filter and throttle cable. Maybe too good to pass up?

[Shaka]

I checked out what that guy is selling.  They are OKO flat slide carbs.  I've heard a little bit of mixed things about them, but I think overall they are good.  Especially, for the price!  I've heard a lot of mixed things about my Arreche also, mostly negative, but mine seems to work well. 

[sidthesloth]

Well, you have had time to learn and set up your carb and it is working for you , so as long as you are happy with it that is what really matters. If someone doesn't like them, well that is fair enough, we all have our own preferences. I on the other hand am learning, so sooner or later I will decide I either like this one or or I don't. But for starting out the price is just way too tempting. Looks like Sid's starting problems has scored himself some oversized cojones. lol.

[Shaka]

Very true!  I think that most of the people that complain about any carb are doing so because they don't know how or can't get it tuned right!  My only real complaint about my Arreche is the availability of alternate taper needles.  I haven't been able to find any!

[sidthesloth]

Maybe if enough people asked for them they might consider making them. Could be worth a try.