KymcoForum.com

Morning all

I have recently purchased a second hand agility 50 and am starting to think I may have bought a bit of a pup. Can someone help with a bit of diagnosis on what my (several) problems might be? I know little about engines, but am a DIY/pull-it-apart-put-it-together-again nut so will likely end up doing any work myself. Having said that, the bike is still under warranty.

When I got the bike about 3 months ago, it had done 1440km (now around 3500km). I suspect it had been in storage for a while, and may have been modded somehow, though the seller “couldn’t remember”. To start with everything was running a-ok apart from the below:

Problem 1 – Acceleration on this thing is abysmal. I’m left for dead at traffic lights by people in lycra. Apart from being quite embarrassing, it’s quite dangerous. Having said that it tops out at 38mph on the speedo. Acceleration curve is rather odd – starts very slow and takes a long time to get to 20. 20-30 is not too bad and 0-30 takes about 16 seconds overall. Then at about 32mph, there’s a second “kick” in acceleration as if someone’s given me a bit of a push, and eventually it hits 38. Any ideas what might be going on? I’m not fussed about losing top end speed just need to improve acceleration. Best guess is someone has installed some funky rollers?

Anyway…having ridden the thing 20 miles a weekday for about 3 months now I’m starting to hit some different problems which may or may not have been exacerbated by the cold weather. They’re quite specific so can anyone help me with a diagnosis?

Symptom 1 – The bike is becoming hard to start, especially when it’s cold. Before the late cold weather, the bike would always start fine on the electric start. Now I seem to have to use the kick start more and more, and it usually takes 2 or 3 cranks to get the thing firing

Symptom 2 – Once the engine is ticking over from cold, for the first 10 seconds if I twist the throttle, the engine will dip and eventually cut out if I persist. After about 10 seconds, it will start moving ok (if slowly – see Symptom 3)

Symptom 3 – For the first 15 minutes of use, when I twist the throttle from standstill, the engine will dip first before picking up revs, then it accelerates as normal. After about 15 minutes, this more or less goes away

Symptom 4 – Occasionally (say one in every 20 rides) the bike will cut out when I hit the brakes hard, and sometimes will cut out at traffic lights when I come to a stop.

Hope that’s descriptive enough to allow a rough assessment. Here’s what I’ve tried so far:
-Replaced the spark plug. The old one had a fair amount of carbonation around it. The new spark plug made virtually no difference to the above problems
-Replaced engine and gear oil. Made no difference.
-Ran redex cleaner through it for about 8 tanks. No improvement (possibly worse?)
-Checked the air filter. Looks fine. Blew a bit of air through it.
-Took the top of the carb (I think). The rubber diaphragm looks perfectly clean and in good condition to me, but I didn’t look any further
-The fuel filter is full of fuel and I can’t see anything obvious in there but I have a replacement on order.


Questions:
-   What is the most likely 2 or 3 things that all this could be?
-   What order should I check them in when getting down to business? (ie. quickest/easiest/cheapest to hardest/slowest/most expensive would be a sensible order)
-   Which of these things is likely to be covered by the kymco warranty? Is the warranty only for parts?

Like I said I think it may have been stored for a few months without use so there may be some varnishing in the carburettor/fuel lines/tank, but I can’t be sure – what is the easiest way to check this?

Any help much appreciated. Am looking forward to getting my teeth into this to learn a bit about motorbikes. Probably the start of my next DIY obsession…