Yamaha Aerox powerband issue

[Elliott Gee]

Hi everybody, i was hoping someone could help me out with a problem that has occurred on my Yamaha Aerox 50cc.

The only modification it has is a Leo Vince Exhaust, when i pull away it is quick to hit the powerband then dies down at around 25mph, it then takes a good 10-15 seconds to hit 30mph then after that it hits the powerband again and all is good.

I want to hear some of your guys opinions of what the issue could be to why it dies down for so long at 25mph. Im thinking it could be a number of problems such as rollers, clutch springs, variator ext. but i havent got a good enough understanding of bikes to pin point the issue.

Many thanks in advance.

[uberkron]

How old? Mileage? Maintained? How does the spark plug look? Has it always ran this way? Did it change one day or gradually?
____________________
i ride a zip 50 2smoke. It overtakes a hundred times a day.

[wr6133]

You have the wrong powerband installed. You clearly have a multi-powerband hence the multiple surges, what you need is a red powerband for constant power.

[andys675]

definitely variator or belt related

there are usually 2 things required to derestrict or make a scooter go faster, this is true of most restricted scooters

1, the engine speed is restricted, usually by the exhaust, just replacing the exhaust is not enough and often harmful to your engine, as now it can do 10000 rpm at 30mph and the engine will wear out faster, a lot faster, creating a load more heat that may also cause seizure

2, the speed the back wheel can spin at is restricted, usually something in the variator needs removing, or replacing to allow the variator to expand which changes the gearing and allows the back wheel to spin faster = more speed, but without the extra revs of the engine speed being improved it won't go a lot faster
____________________
Some people feel the rain, others just get wet.

[Iain.]

TT pipes come with two sets of clutch springs, and a set of rollers unless you bought it used.

https://i.imgur.com/nkMEam5l.jpg

If it's new make sure you pull the restrictor out of the front pipe - pop a screwdriver in there and wiggle the little cone out, it's only tack welded in there.

https://i.imgur.com/ToIlVLcl.jpg

Fit the yellow springs, and the rollers which are from memory 15x12 3.5gr and you'll likely sort the issue. You'll also want a 6mm dellorto jet, probbably around size 68 if you've got an otherwise standard engine or it'll run lean at the top end costing masses of power & risking a heat seizure.

Biggest problem with the Aerox/TT pipe combo is the shitty Yamaha variator - TT pipe likes to be held at a nice consistant point in the rev range to get the best out of it, Yamaha variators don't hold speed precisely at all and dropping a few hundred revs can be enough to drop the engines power output drasticly - Variator upgrades the next thing on the cards.

Avoid the use of the word powerband if looking for sensible answers on here, however you've used it more or less correctly in this case. Given Underrated due to post being well written & making perfect sense