Author Topic: Newbie... Advice please on poor acceleration  (Read 4478 times)

SF11

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Re: Newbie... Advice please on poor acceleration
« Reply #15 on: March 13, 2014, 01:52:22 PM »
Did I already say that it's just a 50cc, and there's not much hope of increasing speed by more than a couple of knots with a tail-wind.  Kymco is no help in de-restricting your moped.  Changing rollers and contra springs won't make a bit of difference, except you will now be short about $50.  Changing the main jet will cost you about $6 including postage, and won't make a stick of improvement.  Cutting the wire on the CDI will add about 1000 rpm, or 5mph, and that's just about all you're going to get.  To get any speed out of a 4-stroke moped, you have to increase the displacement and change the gears.  The cost is about $350 at a shop, and you'll get 45mph (75km/hr).  Now it'll go like a bat of of hell - but it's no longer a "moped" :-)

It does 45mph now... well 50 actually (indicated - probably not that fast in reality)
thats with the lighter rollers, stock contra, CDI cut so that it now revs properly, and main jet had been changed previously. Restricted it's 30mph flat out, so that's like a 50% gain already, and yes, probably would be hard to squeeze much more out of a 50cc motor.

Might go down the road of a BBK if I get a cheap chinese project scooter to tinker with, but I'm leaving the Kymco pretty standard tbh.

JJJoseph

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Re: Newbie... Advice please on poor acceleration
« Reply #16 on: March 22, 2014, 07:22:48 AM »
if I get a cheap chinese project scooter to tinker with, but I'm leaving the Kymco pretty standard tbh.

LOL!  The Kymco Agility/Sento 50cc is already a "cheap chinese project scooter"!  Most of the Kymco coachwork is good quality Taiwan stuff, but the engine is a standard off-the-shelf made-in-China qmb139 beater and you can use any of the qmb139 go-fast parts in it.

blue

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Re: Newbie... Advice please on poor acceleration
« Reply #17 on: March 22, 2014, 11:05:19 PM »
Do not remove the airbox restrictor unless you're ready for a headache.

That thing affects the bike alot for being so little

I took my whole air box off and ran open air filter. cut cdi box and bigger main jet.and ran 5.5 rollers and my scoot did 45 to 48 all day for like 4 years.The only reason why my scoot stoped working was do to a bog pot hole and I broke the crank cover and the motor right in half. What a ride it was.............

Smithg27

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Re: Newbie... Advice please on poor acceleration
« Reply #18 on: May 01, 2014, 05:18:30 PM »
This JJJoseph guy has no idea what he is talking about. lol He has clearly never owned a Kymco Agility 50. He posts on so many of these Agility 50 posts telling everyone how they will never get 45mph out of their Agility. When in reality almost everyone that does the small 3 derestriction mods get 45mph. He also says that the engines are standard chinese qmb139 engines when in fact they are not. Kymco took the qmb139 and adjusted it to their own design.

So PLEASE JJJoseph stop commenting on these Agility 50 posts with your nonsense! Save everyone the confusion of your lack of knowledge and let the people who actually know Agility 50's comment on these posts.

zombie

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Re: Newbie... Advice please on poor acceleration
« Reply #19 on: May 01, 2014, 10:09:17 PM »
I don't want to fuel a fire...
 I have worked on at least 3 Kymcos in the past that had QMB139 engines.
I believe WordSlinger also has/had one. He bought his brand new from a dealer.
 From the best I can figure  Rongfa Motor Engine Co. Makes the engine cases. The cases are stamped with whatever the buyer wants.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

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