KymcoForum.com
Scooters - 50cc => Super 8 => Topic started by: Kieren on November 15, 2009, 03:47:05 PM
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I've had my 6 month old Kymco Super 8 50cc 4stroke a few weeks and have since fully de restricted it.
I've changed the boss for a de-restricted one, put a size 84 jet in the carb, cut the 2 purple (with red highlights) wires on the CDI and swapped 3 of the rollers (was told this was ok by a bike mechanic) for 4.5g rollers and kept the 3 originals (in an attempt to get good pull on hills and still have a decent top end).
But the bike goes above 30mph but then struggles to get into the high 30s.
Is there something im missing here?
I don't expect super speeds out of a little 50cc but my last scooter (unreliable thought it was) made 40mph (45 if you really pushed it) so for a higher quality and higher priced scooter i would like it to do 40 easy.
Thanks in advance for any help...
EDIT:
According to another website I've found i need to remove a restriction in the air box and there is a restriction underneath the carb / on top of the inlet manifold
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You should be getting better speed! The first obvious trouble is the rollers. They must all be the same weight for long term stability. The heavier (stock) rollers will be doing all the work, while the lighter ones will float. It seems 5.5 gram rollers work the best w/ the 4t engine. you will have a total of 33 grams. Also changing the clutch fly weights will give back the low end torque. You will want to install a heavier set of these, (stiffer). Being a new scoot I believe your trouble is in the set up of the cvt more so than any other cause. Have you also changed the main friction spring in the clutch? This will also give a smoother overall feel to your scoot. Also pull off your muffler, and take a look into the manifold end of it. You are looking for a 1/2 moon re-stricter that must be filed/ dremeled out. I may have missed something but these are the basics.
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You should be getting better speed! The first obvious trouble is the rollers. They must all be the same weight for long term stability. The heavier (stock) rollers will be doing all the work, while the lighter ones will float. It seems 5.5 gram rollers work the best w/ the 4t engine. you will have a total of 33 grams. Also changing the clutch fly weights will give back the low end torque. You will want to install a heavier set of these, (stiffer). Being a new scoot I believe your trouble is in the set up of the cvt more so than any other cause. Have you also changed the main friction spring in the clutch? This will also give a smoother overall feel to your scoot. Also pull off your muffler, and take a look into the manifold end of it. You are looking for a 1/2 moon re-stricter that must be filed/ dremeled out. I may have missed something but these are the basics.
So basically go back to the standard rollers, i may have to buy new ones as they all seem to have flat spots (if anyone could let me know if this is good, bad, normal or what causes it i would really appreciate it!)
Change the clutch springs? I think that's what you mean? If so something like these 'http://www.centralscooters.co.uk/product_info.php?cPath=514_657_677_497_626&products_id=3820' (http://www.centralscooters.co.uk/product_info.php?cPath=514_657_677_497_626&products_id=3820') ?
Then get one of these? 'http://www.centralscooters.co.uk/product_info.php?cPath=514_657_677_497_626&products_id=3832' (http://www.centralscooters.co.uk/product_info.php?cPath=514_657_677_497_626&products_id=3832')
Check the exhaust and for the cvt i assume that all falls under the rollers and clutch springs?
Thanks for your help, i know im asking a lot of questions :D
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Those are the clutch parts your are looking for. I'm gonna take up with Zombie and say the different rollers are probably the culprit. Flat spots are normal wear, also the cause of not hitting top gear. Flat spots will also occur much quicker when using different weight rollers! I have had real good luck with the Dr. Pulley sliders, they don't wear nearly as fast as rollers! The clutch springs will give better overall performance, but not really effect top speed. Definitely check the exhaust for a restricting washer. I think I have heard about super 8's having that restriction as well.
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According to my dad when we had the exhaust off (to get the wheel off to get a new tyre fitted) he checked and there was no kind of restriction in the end of the exhaust.
Also i was running it before with just the 4.5g rollers and then only really made around 30 (not much higher). May well try just the original rollers but then may not make it as well up a long hill i have to go up once a week.
If all else fails it's still under warranty so there must be something wrong with it if it doesn't go much above 30 with the original rollers.
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Something is going on, you should be getting a higher speed than 30mph! I have also heard of some exhaust having a restriction in the middle of the pipe, that there is no easy way to remove. For those you just have to get a replacement exhaust. You may have to do some research and find out which exhaust you have. I'm not sure of any restrictions in the air box or intake manifold. You probably have to take those parts off and check.
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If you go back to the dealer, perhaps you could "persuade" them to install the springs, and new rollers/ sliders for you. A good shop can do the whole thing in about an hour. If you explain your driving route, and "how unhappy you are" they may just help you out a little! You mentioned your rollers are getting flat already! Even though the stock rollers are not very good, they should not be wearing soo quick. If you go ahead, and set it up correctly, the difference will be worth it. Keep posting so we can see the outcome!
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If you go back to the dealer, perhaps you could "persuade" them to install the springs, and new rollers/ sliders for you. A good shop can do the whole thing in about an hour. If you explain your driving route, and "how unhappy you are" they may just help you out a little! You mentioned your rollers are getting flat already! Even though the stock rollers are not very good, they should not be wearing soo quick. If you go ahead, and set it up correctly, the difference will be worth it. Keep posting so we can see the outcome!
I didn't buy it from a dealer, might be able to get a Kymco dealer who does warranty work to have a look at it though?
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It sure couldn't hurt! If there is a problem that is causing the rollers to wear too quick they may put in the good parts for you, or at least you will have a clean slate to work from! Good luck.
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Went to my local dealer today but the mechanic wasnt there.
The other guys tried to help me out but didnt have any ideas either!
They are supposed to be getting the mechanic to phone me back, if not il arrange to get them to look at it friday (hopefully under warranty so no cost?)
I took the little restriction out of the air filter today but still no luck!
I ran it on the stand and gave it full throttle it when to what seemed like full rpm then died down a bit then came back again :S
I think this was just because it was cold but who knows!
Hopefully they'll look at it Friday
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Now I'm not SURE about this but the de-restriction on the cdi is supposed to be cutting ONE of those wires (purp/r). I have never looked into exactly what the circuit is so I don't know what cutting both will do. To be on the safe side I would use a butt connector to put 1 back. Good luck w/ the dealer/ mechanic! Please let us know how you make out...
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Now I'm not SURE about this but the de-restriction on the cdi is supposed to be cutting ONE of those wires (purp/r). I have never looked into exactly what the circuit is so I don't know what cutting both will do. To be on the safe side I would use a butt connector to put 1 back. Good luck w/ the dealer/ mechanic! Please let us know how you make out...
This was one of the things i was thinking, I'll re-solder one if no difference try the other.
If everything fails i think i'll just re-restrict it...
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Na!!! Don't give up so soon. Those wires make a loop. They are going to something inside the cdi. I have talked to Suitai about the failure rate on their cdi's, and their explanation is the 2 stroke model is shorted to de-restrict, creating more current (heat) to the cdi. The 4 stroke is a loop that when de-restricted, eliminates a circuit that in turn forces other circuits to work harder (again more heat). Suitai has engineered their stuff to work pretty well, and can program a cdi for you, if you find yourself getting into tuning. For now stick w/ it. One step at a time is best. You'll get there!
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I'll give it a blast Friday then (day off), just borrow someone elses soldering iron and solder then take it for a whizz.
What have i got to lose?
I'll also try only 6g rollers and.. well if that is no help Kymco i shall phone!
They never seem to respond to emails so maybe they are better with phone calls...
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No doubt!
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Tomorrows plan of action:
-Try a different exhaust
-Try different rollers
-See how many clutch turns for a full wheel revolution
-Try 7g rollers
-All above fail, re-solder one wire on CDI
If its the exhaust then the replacement should be a performance exhaust me thinks 8)
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Where di the scoot originally come from? The reason I ask is there are many different set up depending on the market it was built for. The rear gear set SHOULD be ok. The 5.5 gr rollers seem to work best on the 4 stroke engines when combined w/ stiffer clutch fly springs. The heavy rollers will give a better top end; true but the lower rpm's will suffer ie:hill power. The super 8 is a super scoot. It does need to be set up correctly, and most of what you have to do depends on the sale market. The most consistent improvement is in the cvt. I would highly recommend 5.5gr rollers, and Malossi clutch springs as a GOOD starting point. Deff. reconnect 1 of the cdi wires also (just to be sure). I understand it is a new scoot but has anyone done a compression test on it? a quick check should show at least 100 lbs. 110 -120 is perfect. also the valve adjustment is critical on that engine. I believe it is .04mm. search some of the posts on this site using keywords, and you will find more specs. I do know the cvt set up I recommend is good, and I trust your gear set is good. Do the valve check, and the compression test to be sure you are ok there, and take things 1 step at a time. If you change multiple things at once you dont' really know what did what. ROCK ON~
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I would assume it came from the UK seems as thats where i bought it and am riding it, somewhere up north if that helps (Haven't got log book yet)
Not going to start customising extra stuff like clutch springs etc yet though seems as it should be doing 45mph stock al be it de restricted.
I know roller waits will make lower end suffer but it pulls bloody well as it is so should pull well still with heaviers, it feels like its somehow restricted still seems as it stops at around 30mph at what sounds like full rpm (got over take by a 50cc that was still restricted down hill today!)
Mechanic my dad spoke to today also said about gear setups i.e its either got the wrong gears from stock due to a balls up in the factory or some tit has changed them to try and derestrict.
He also said he only does all the stuff we've already done when he de restricts them and they do 45mph easy.
If everything i try doesnt work i think Kymco SHOULD replace it / fix it as it should do 45 and is still in warranty.
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Absolutely "bloody well right". I had to laugh out loud! Hope you get to also! Just try to keep the bugs out of your smile doing 45+
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19:1 !!!!
19 turns of the clutch for one full wheel revolution!
No wonder it only does 30, the engine must be working over time :o
New gears me thinks?
Couldnt try the other exhaust because it wouldn't fit >:(
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Anything is possible. That's why I asked where it originated. Some countries are more strict than others on the set up they will allow. Sounds like you got it under control. Please post back to let us know how you make out!
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A Bit of a late reply but this may be useful for anyone reading; the bike may not be reaching high speeds with all of that stuff done to it because you cut two wires in the CDI, you're only meant to cut ONE(i can't remember but i think it's light purple?).
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Luke is right about the cdi. Can you post up a pict of yours, and the wiring? If not what colors are the wires. And are you sure about the gear ratio? 19:1 will climb a wall but su<k on the road.
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Sorry for the threadjack but when I had my cvt cover off last week I counted turns of the clutch bell and it was 10 and 2/3rds to one revolution of the rear wheel. This is standard I guess?
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Shaka's zx was around 11:1 I think. The s8 should be slightly higher, but 19:1 sounds like that may be the restriction. They change the method for each country so I am sort of clueless there. A call to Kymco UK, or a knowledgeable dealer may be in order.
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10.6:1 is the stock gearing in the ZX.
Got 8.6:1 now! ;D