New ZX50 owner with a few questions

[pcslayer]

Hi everyone,

I've been reading through this forum researching Kymco for many weeks now and all your postings helped me decide to give Kymco a try. Was just waiting for the right bike (for the right price) to pop up on CL and it finally happened 3 days ago: a red 2005 Kymco Super Fever ZX50 with 968km on it for $320. The previous owner rode it for a year and then put it in storage for the next 4 years until he decided to sell it. It's got a couple of scuffs on it but she still looks beautiful.

I put on a new battery and had the carb cleaned and that's all that it needed. Man, does it run nice! Even at an indicated 40mph it is crazy fun (I understand the actual speed is closer to the low 30's). The previous owner said that he did not have it derestricted so now I get to do it. I first went for the easiest (splicing green and light green CDI wires together) and now she's up to an indicated 45mph. Next I want to do the variator but I can't seem to find the right part. I've read people paying in the vicinity of $12 for one and all I can find are things that look and are priced like this:

http://www.mhr-usa.com/scooter-variator-kits/jasil-sv1-variator-kit-for-kymco-2-stroke.html

Obviously not the same price range as $12. In older posts there are some ebay links but the links no longer work.
1) Can someone please help me by pointing me in the right direction?

2) Now what’s the difference between replacing the variator and doing this?
http://www.scootertherapy.com/bosspage.html
Could this be what cost some people $12?

Also if someone has messed around with different types/brands of spark plugs I would like to hear about that too.
3) Basically which one is the best?

My right brake lever came bent. Highly recommended Stadium Yamaha has them for ~$13 but only has them in black. I’d obviously have to get both sides replaced then so they match. Kymco Parts Online has the silver ones for twice the price so it ends up costing me the same. I realize this is all pocket change but it got me thinking:
4) Any other good source of parts for things that could potentially be generic (and therefore cheap) like levers?

Finally, I am on a budget for right now and so I am not planning on spending a lot on BBK’s or fancy exhausts (I will some day though). But for right now I am sticking with what can get me a little more speed on the cheap. I realize that I cannot expect miracles so all I want is to get the highest top speed possible while staying within a budget of $200-ish.
5) Which mods would you recommend to get the most mph’s per $? (and yes, I am already on a diet  ).

It’s great to finally be part of this community. Thanks in advance.


DISCLAIMER: Complete noob here! All I know is what I've read here. I have worked on a dirt bike and an atv before but even though I had a scooter many, many moons ago; this is the first time I will be working on one, so please be patient. I do promise I will search and read before asking. Thank you!

[thebatman]

All you really need to do at this point.......oh yeah, WELCOME TO THE FORUM....
In sead of swapping the whole var out is shave/file/grind the "shoulder" that's on the drive boss..(that's what that thing is called). In your 2nd link, in the pics you can actually see that shoulder i mention... Somebody does sell them but i cant remember right off where.. A new var will help with "shifting", making it smoother and possible extra mph on top...scooterassassins.com(they also on ebay has cheap variators for sale, i rode one of those for a long while myself)
I just use the ngk bpr8hsa, after the build i did go to the 9 series..(you'll be good with the

Alot of brakes levers, mirrors are universal fit, so i'd say you could get the levers at 13 a PR. somewhere like ebay....
For a bit of stock performance you can install a pod filter($15?), drill you 6 3/8" holes in the rear under side of the exhaust(free), rejet the carb(which may or may not be needed, plug chops will tell you that)(can be free), swap out for some 6?g rollers(the oem are 8.5gram)(good ones are $17)...check the squish clearance/shave the head for correct squish(maybe $20-30 @ a shop)..(i had gotten 4mph on top with that alone)...

As to the mods, the pipe will be a good thing, the squish, rejetting and a variator... But of course that bbk is frkn great!!!!!!!!!!!!!!
Hope this helps you sonme, just let me know if i can help anymore....or at all.....

[pcslayer]

Thank you much for the reply thebatman. I’ve read so many of your posts. Thanks for sharing everything you know.

1) So I took here apart with the intent to shave the boss drive but as soon as I removed it I realized that the boss drive didn’t have any “shoulder” on it. It looked just like this one:

http://www.exportstrength.com/product_info.php?products_id=403

I’m just not sure I see it clearly in the scooter therapy link that I posted originally, but I assume the “shoulder” is a small section of the drive boss where the diameter is slightly larger than the rest of the cylinder?

If yes, then I assume that the fact that mine looks like a perfect cylinder means that the derestriction had already been done, right?

If anyone has a picture of (or a link to) the stock one with the shoulder still on it I’d like to see it just to be sure.

Anyways I guess I need to go measure my actual speed with a GPS. I assumed I would be getting 45mph after the two mods, both of which it seems I already have. Thing is my speedo is reporting 45mph and I understand that it likes to exaggerate, so really I’m getting sub 40mph?

2) Now onto thebatman recommendations. I’m not sure I want to drill holes in my exhaust or do any head shaving (I don’t want to take my engine apart yet). I don’t want to make irreversible (or difficult to revert) changes. That’s great info though. So I guess that makes it so that I will have to fork out some dough if I want some more speed. So how about this?

What if I got this exhaust?
http://www.provoscooter.com/scooters/kymco/kymco-zx-50-2t-ac/tecnigas-next-r-expansion-pipe-chrome-honda-dio-kymco-dj.html

Along with a Pod Filter (recommendations?), 6g rollers (should I get Dr. Pulley’s?) and rejetting the stock carb, that shouldn’t take me too far off my $200-ish budget.

So, what would be my approximate speed increase?

Am I missing anything that must be part of this package in order to gain some speed without destroying my engine prematurely?

I wouldn’t HAVE to do the head shaving, or would I?

Thaks again!

[thebatman]

Hey man, thanks for reading my posts.... As you have read, it gave me MANY headaches...
I do miss the guys we had around back then...
As for a pod filter, of course the best(to many ppl)would be a K&N open air/pod filter... Of course my broke ass will go to the local cycle shop and get a $10 knock off..(they do work.)

Yeah, if your drive boss looks like the one in the link, then it's already done.. Good deal. At that same place, he sells a cheap variator, A variaitor does help too, OF course the best of those would be the malossi multivar.  .(the same site as the pipe sells those but they are $109)

Yep, that's the pipe for you. You could actually even use that pipe if you ever bbk it, but of course it wont be on TOP form withoput an actuall 70 pipe at that point(ie: the technigas rs2,dam good pipe, a yasuni is the TOP i'd say but they are around $400)

I think it was the 2nd or 3rd pic in that original link that you could barely make out the "shoulder" i mentioned but yes you are correct about the "shoulder", it has a bigger diameter on the end.

If possible, get a "roller tuning kit". That will help you out in the future when you need to change the rollers when you mod something. I had a top of 53mph and still with the oem cylinder, it was a dam good day that day tho..(ie:temp,humidity,etc.,but i am up in the mtns at like 2225ft)I would definatelt recommend gettting the head shaved to set the squish. A shop shouldn't charge anymore than around $20 for that, you provide how much to take off of course, I got 4mph on that mod alone.. YEah, the speedos are off with the 110 tire on the front, but i had upgraded my tires and it actually made it dead on with the gps, i installed a 120/70 front and a 130/70 rear, but the speedo will be off 5mph with the 110/70.(mine was).

There is no danger in destoying your motor.........Yet anyway...
I hope this helps again,asking is what i had to do, just stay paitient and you'll geta win. The "modding bug" is a bitch....

[pcslayer]

Thanks again for the reply thebatman.

So bigger tires sounds like a great idea. I assume the scoot then “catches up” with the actual speedo then? So say, since my speedo is currently reading 45mph (probably a REAL GPS 40mph) with the new tires (front and rear) I WILL be achieving a REAL 45mph? If this is true, it sounds like just the rear tire change will give me an extra 5mph and the front one is what will make the speedo reading accurate. Or am I missing something here? Also, do these tires slip right in without needing to take off (or mod) the fenders?

Regarding your original post suggesting to drill holes in the stock exhaust. I am just curious. Where would these holes go? Any pictures? I know this will of course make it louder, but with that and the Pod Filter is it a LOT louder? How is the noise compared to getting the Technigas? I really don’t want to piss off my neighbors.

I also saw on scooter-assassins an exhaust that looks like the stock but it says it is unrestricted. Anyone tried that one?

Here’s the link to it:
http://www.exportstrength.com/product_info.php?products_id=677

BTW, on that website when looking for parts for my 2005 Super Fever ZX50 it shows two options:

ZX 50 ( Fever II ) ZXII

and

ZX 50 (Fever) KCA Model

Which one do I have?

I’m in the US BTW.

Thanks!

[thebatman]

I personally liked the tire swap.. I'm not sure how that all works...
If you do a 130 in the rear, there is a spot on the case that you will need to "grind" away for just enough clearance, it's nothing though. Otherwise the fenders are good...
I drilled the holes on the bottom side of the exhaust "canister"/muffler at the rear toward the end. i did 6 holes,2+2+2 in a line. That really doesn't make it that much louder. It actually gave it a deeper/throatier sound. Sounds better.. (im sure your's still has the catalitic converter also,which helps stay quiet....i beat mine out.. )...
The technigas really isn't that loud either, they get louder when the "packing" gets worn.. Repack the silencer and it's quiet again.
I don't know of anybody that's used that pipe, looks heavy too. The oem pipe is real heavy compared to the technigas next r, it's real light.. which helps get rid of exess weight on the sccot.
Actually either will work when looking for parts but you have the "kca".. The only difference is earlier on (01-02)they used a 10mm wrist pin,(03+ uses a 12mm) and the paint scheme is really the only thing. That place actually list the same parts on "both models". no biggie there..
Wher bouts are you located in the states? jw.

[pcslayer]

Hey bat. Thanks again for your reply man. I read what happened to your ZX50. Hope you can get her up and running soon. I’m in the beautiful Sonoran Desert in the Phoenix, AZ greater metro area. I can ride out here just about 350 days out of the year and it’s all just flat land so I don’t have to worry about hills.

I think I am going to experiment with the tires then. I want to go faster but I also want to know how many mph’s each of my mods are contributing. I am going to put the rear one on first and do a max speed test. Compare GPS vs. speedo. Then put on the front and re-measure.

What are the recommended tires for these sizes? I saw some Michelin’s. I’m sure those are good. But I see Kenda, Pirelli, Shinko, Continental and Bridgestone also. Any tire suggestions?

Ever hear of Vee Rubber? ScooterWorks is seeling a 130/70-12 on Amazon for $29.21 shipped!
http://www.amazon.com/Scooter-Tire-Rubber-Sport-70-12/dp/B003JO4CQW/ref=sr_1_1?s=automotive&ie=UTF8&qid=1313559604&sr=1-1

I verified today on my GPS that I am able to hit a real 42.5mph max speed while my speedo was indicating an approximate 47.5mph confirming the 5mph offset you mentioned. This is with just the CDI and boss drive de-restrictions that I have so far.

I read a post yesterday from some guy (jimboduncan) saying to just drill out the stock exhaust, but his approach was a little different than yours…

http://scootdawg.proboards.com/index.cgi?board=2stroke&action=display&thread=36413

Interesting information. I’m reconsidering and thinking I might give either your or his method a try, but if I do that along with a pod filter, do you remember what size jet you had to use?

Thanks!

[thebatman]

What up pcslayer? Sorry for the long absense.....
A 90 main jet should be good for you with those mods.. On the oem carb, i tried teaching myself to drill the jets out myself because at that time i had a FIT trying to find THOSE jets anyway..(it seems the zx carb is different even tho its a kiehin. , drilling turns out to be pretty easy just a bit more work...)
Hope this helps, keep us posted...oh yeah, where is some pics?..

[pcslayer]

Hey bat no prob. Thanks for yet another reply. Sorry for the long absence here also. Have had a lot of work. Just got my new Tecnigas Next R yesterday. Will install this weekend and send an update on how it went along with some pics of course. Right after that I am getting the rear tire. I want to do one at a time to see the effect each mod one has.

[thebatman]

Sounds like a plan... Keep us posted.

[pcslayer]

Sorry for taking so long to get back here. Life has been throwing a lot of curve balls that have distracted me from my bike, but anyways here I am again with another inquiry. I am completely puzzled. I finally installed my new Next R pipe. The pipe came with ~5.5g rollers but I didn't install them yet. The reason I didn't is because I was under the impression that if I kept the stock rollers that I would get a higher top speed being that these are ~8.5g.  My logic is based on: heavier rollers = higher top speed but lower acceleration while, lower weight rollers = lower top speed but higher acceleration. Well, turns out that I did a test run and gained 0mph. I basically saw no speed improvement whatsoever. I was doing a GPS-verified 42.5mph top speed with the stock pipe and with the new pipe I saw the exact same top speed. Based on the logic above, I would think that putting in the 5.5g rollers would lower my top speed. So my questions are: Is my logic correct? Or am I missing something? Would the 5.5g (or other) rollers actually give me more top speed?

Another thing I wanted to ask about is I bought the pipe from Provo Scooter and on their website it shows the following note for the Next R.

"NOTE: Due to increased emission regulations all Tecnigas exhaust now come with the washer restriction in the mounting flange, which should be removed to get maximum power gains."

I didn't see any washer on the mounting flange (which is the input to the exhaust pipe right?). Is the washer inside the pipe? Would kind of defeat the purpose of getting an aftermarket pipe though. Did I miss the washer somehow?

Thanks for your help!

[thebatman]

Hey man, I was wondering how it was going. I know what you mean by the curveballs!!
Did you install the filter? Did you do a plug chop?
Did you change any springs?(i don't think you were)
I would say that the 8.5's are to heavy, It seemed that everytime i changed something, it would throw the cvt out. Try sum 7.5's?

[thebatman]

Hey man, On my pipes it did not have the restricter cone.. Here is a pic of a LEO exhaust and you can clearly see the cone. If you don't see something to this effect, then you shouldn't have any....

I had run 7-7.5g's for quite awhile.....

[thebatman]

TRy this pic... IDK WTH i did there...

[pcslayer]

Hey batman, thanks once again for your reply. I didn't install the filter yet. With the plug chop I don't even know where to start. I don't understand it and it looks really complicated; plus I wouldn't even know where to take it around here. I haven't changed any springs either. Should I? I couldn't try the 7.5g rollers because I don't have a kit to try different weights. Obviously I'll need to order one of those. I should have thought about it sooner. Any recommendations for a kit? What I did try was using the rollers that came with the pipe. Those are 5.5g. I saw no improvement on top speed (but it didn't get worse either), so this just further adds to my confusion. It looks like I'm stuck at 42.5mpg no matter what! I don't get it. I thought the pipe itself would add at least a few mph. Oh, and yeah. My pipe doesn't have that cone inside the exhaust. It looks like it's free of obstructions so then WTF!

Tomorrow I am putting in the Michelin 130/70-12 rear tire. I have a feeling that this will make it go a tad bit faster.

As I said before. I want to do one thing at a time because I want to see how each "upgrade" contributes to my goal.

So I guess this is like gambling, once you've spent X amount you don't want to leave the table because you feel your luck is about to break your way. So what should I do next to get me that extra speed? I don't need much. I just want to get to ~52mph.