Newbie... Advice please on poor acceleration

[SF11]

Hey everyone, I've just bought a 2011 Agility 50 mainly to be used for commuting to and from work.

The scooter has already been de-restricted by the bike dealer that sold it to the folks I bought it from, but they were unable to tell me exactly what has been done to de-restrict it.

On my first run home on it the other evening, it felt like it just didn't want to rev very high. Having trawled through the forum here, I read up on the CDI mod, the variator boss and the main jet upjetting mod. The CDI had already been cut but I wasn't convinced, so I removed the silicone sealant that had been used to seal the cut mark and couldn't see any signs of sawn through copper wire, so I decided to cut a little deeper, and that's when the insulation for the wire then appeared, and I cut through it.... Scooter revs much better now. While I was there, I removed the transmission casing and checked the variator boss. I think this has already been changed for a smooth one. Would I be correct in saving that the raised part of the restricted boss would be visible down in the well of the pulley?

I'm not sure whether the main jet has been replaced or not, and I don't have a set of jet size gauges.

I took the scooter out for a run today in the dry, and managed to get an indicated 70kph ~43mph out of it, which seems not bad, but the main problem seems to be trying to accelerate after slowing down, say after coming out of a bend, the engine seems to be at too low a speed, as if it's in too tall a gearing.

Pulling away from a standstill seems to be ok... The acceleration is quite linear.

Any suggestions as to what to try first. Lighter rollers perhaps? I'm new to the CVT thing, but have a reasonable handle on the theory of how it works...

Cheers.

[blue]

from waht you are saying yes the rollers might help. try any wear from 5 to 6 gram rollers.I find any less then 5 the scoot will barly move 5.5 works great for me I can climb hills at 35 and top out at 42 to 48 thats about the best you can do with out adding to much coin to your scoot. maybe a wider belt but I find stock is just fine.

[wordslinger]

I gotta agree with blue on the rollers...5.5 work well in an agility..

..I would also suggest installing a 1500 torque spring...it's within the driven pulley / clutch assembly...

..that will work wonders on accelerating out of the curves...


Welcome to th' Forum!!


   

[SF11]

Thanks for the replies 

I've ordered a set of 5.5g rollers and a 1500rpm contra spring and will post back once fitted and tested...

[SF11]

Update:

Parts arrived in the mail today, however I quickly realised I had ordered the wrong contra spring (for a 125 instead of the 50...)

So I went ahead and fitted the 5.5g rollers anyway with the stock contra spring.

Vast improvement in acceleration already, and able to climb a hill at 30mph that usually slows the scooter down to 20 mph, so I'm pretty happy about that result. I'm hoping the new spring will improve things a bit more  when it arrives.

[wordslinger]

..AWESOME!!

..and you will simply LOVE that 1500 contra..

..best thing, other than open air mods, that I ever did for kymmi..

[SF11]

Oh no

Fitted the 1500 spring today, but now it won't pull over about 20mph! I think I will need to go back to the stock spring or maybe get a 1000 to try...

[wordslinger]

..yeah, when I was running the 1500, kymmi had K&N air filter, HUGE main jet, Malossi variator, Stage 6 clutch, longer belt, modified exhaust, and I had also modified the needle retainer in the carb, so that it was .025" higher...

..you're gonna LOVE that 1000 contra!!


                 

[JJJoseph]

Save your money. I'm guessing the contra spring won't make much difference.  It's just a 50cc, and there's not a lot of room for improvement.  Your biggest bang in acceleration will be from increasing displacement, though your top speed still won't change much.  But the acceleration will be awesome! Regarding jet sizes, the size should be stamped on the jet (use a magnifying glass).  A #80 jet is 0.80mm diameter.

[Resolve]

Oh no

Fitted the 1500 spring today, but now it won't pull over about 20mph! I think I will need to go back to the stock spring or maybe get a 1000 to try...

did you get a new contra spring for the 50cc or did you use the 125?

There is no need to improve displacement just for acceleration unless you want to reduce the longevity of the scooter.  There are plenty of options to inprove acceleration.  But being a 50cc they are still limited.  right now you are going in the right direction.  But if upgrading roller weights and contra spring why not just upgrade variator also.  that will also help.

Upgrading the variator also has to potential to increase your top speed around 5 mph.

[SF11]

did you get a new contra spring for the 50cc or did you use the 125?

There is no need to improve displacement just for acceleration unless you want to reduce the longevity of the scooter.  There are plenty of options to inprove acceleration.  But being a 50cc they are still limited.  right now you are going in the right direction.  But if upgrading roller weights and contra spring why not just upgrade variator also.  that will also help.

Upgrading the variator also has to potential to increase your top speed around 5 mph.

No, I sent back the spring for the 125; it's physically much longer than the one for the 50cc. The supplier swapped it for the 50cc 1500rpm spring.

Today I tried a couple of things while on my lunch break:
Firstly I was going to try the stock rollers back in with the 1500 spring, but on closer inspection, a couple of the rollers were quite badly flat spotted, so instead I tried 3 stock and 3 of the 5.5g rollers, then road tested. Better than it was but flat out was limited to ~35mph....

I then re-fitted all the 5.5 rollers and went back to the stock contra spring. This is a much better result: pulling 35mph up a long incline and flat out indicating 45mph on the way back (downhill).

I could call it a day at this point, as those sort of figures are acceptable for the use that I'd be giving it. It seems happy enough cruising at 40... Though I think I will order a 1000rpm contra spring just with the fact they're not that expensive. I'm also considering a Malossi multivar, as I've read some really good reports about them, but that's a bit of an upgrade....

The stock variator doesn't look amazingly well machined tbh, especially where the rollers fit, which I assume to be a fairly crucial part.

In other news, I can strip a variator and clutch off in jig time now! :p

I think for BBK etc, I'd rather just buy a cheap Chinese project scoot and fiddle with that for giggles rather than abusing the Agility too much...

[SF11]

One other thing... On the hose linking the air box to the carb, there's a sort of raised rubber 'washer' for want of a better term. I'm thinking that will be reducing the airflow somewhat, not to mention causing some turbulence? Is that worthwhile getting rid of and possibly up jetting afterwards?

[wordslinger]

..my agility ran it's best with a multivar..and I tried many others...

..I would suggest using Dr Pulley sliders, if you really want to boost performance a bit..

..as far as the rubber....removing it should not require any jet increase, but you might want to do a plug chop after you open it up...

[JJJoseph]

On my first run home on it the other evening, it felt like it just didn't want to rev very high.

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" :-)

[245luigi]

Do not remove the airbox restrictor unless you're ready for a headache.

That thing affects the bike alot for being so little