Kymco AK550 - CVT and

[AndrewS33]

Hey everyone,

My name is Andrew and I'm an AK550 owner and I'm looking for some advice and suggestions. I bought it a few months ago with very low mileage, just 1600 km (990 miles).

I've noticed something and I'm not sure if it's normal for this model or if it's something that needs fixing. When I'm riding and slowing down (like approaching a traffic light or a pedestrian crossing) and I completely let go of the throttle, when the speed drops to around 20-25 km/h, I feel a slight jerk as the revs switch to idle. It sounds a bit like riding a manual bike in too low a gear. The CVT isn't perfectly smooth when decelerating with the throttle off. This doesn't happen when I'm coasting to a stop or slowing down downhill.

Is this normal? Unfortunately, I don't know anyone else with this bike to compare. I used to ride smaller CVTs (125cc) and it felt smoother when approaching traffic lights etc.. Otherwise, the scooter rides great, accelerates fast, and is very smooth when accelerating. I changed the oil (motul 10w40 jaso ma) a month ago and didn't notice any difference or improvement. Could this be an issue with the idle adjustment? Or maybe something to do with the CVT settings/regulation?

Thanks!

[Stig / Major Tom]

Many scooters are not at their best when leaving a stop, or approaching one. Some better than others,  (and riders techniques can really affect how their scooter launches.)
Probably nothing wrong with your scooter...but other owners will respond here.
Stig

[rjs987]

Welcome to the forum.

I just returned from a 1379 mile trip from Iowa to TN and back (with a few days of camping in between).

My 2022 AK 550 now has 14925 miles (24019 km) on it. I bought it new. Before that I owned a 2013 Burgman 650. It's more about the RPM than the speed with a CVT. When slowing down and the RPM drops to around 1500 or lower the clutch automatically lets go and then the rear is freewheeling like when you pull in the clutch on a manual transmission bike. You will notice more engine drag before this compared to some manual transmission bikes depending on what gear those bikes are in when starting to slow down. There are no "gears" in a CVT when speeding up or slowing down. The clutch will grab again when accelerating somewhere around 2000 RPM. I was able to more closely verify this with the Burgman which has an analog tachometer.

What you may be feeling and experiencing is that moment when the clutch lets go and the engine simply goes to idle. Then you will just be coasting freely. Bigger super scooters like the Burgman and AK are more noticeable when that happens and it does sometimes feel like a slight jerk. This is totally normal. A smaller scooter might not be as noticeable, if at all noticed, but it does still happen with those.

My wife rides a Honda Metropolitan 49cc scooter and it also does the same though not as obvious.

BTW- good choice on the oil. These super scooters have a wet clutch so they need JASO MA or MA2 oil or the clutch plates will be damaged. You picked the right kind of oil. I now use SuperTech 4-cycle motorcycle oil which is also JASO MA2 certified (the bottle with the picture of the sport bike on it). I used to use Shell Rotella T6 until that became sometimes unavailable for a good price.

Oil filters are the same as used on BMW bikes so I bought the BMW oil filter cap wrench from Amazon to make it easy to do the complete oil change without removing ANY panels.
I've posted in this forum on some of the maintenance I've done on the AK.