2013 50cc TaoTao ATM50-A1 scooter losing speed By hitshane (Read 1,495 times)

[hitshane]

Hello,

    So, my 60cc scooter has done 40-50MPH since I bought it new. I have upgraded the vacuum lines, fuel lines, fuel filter, carburetor, and modified the day running low beam headlight, to turn on with the high beam switch only. I have had valves adjusted and oil(s) changed twice since I got it and have 1200 Miles on it.

    Over the last few weeks it stopped going 50~ and started maxing out at 30~. It has very fast acceleration and passes most cars from a stop until top speed, but the top speed was now 30mph!!! I have been messing with the carb, plug, hoses, gasket bolts, wiring; everything!

    I was just about to order a torque wrench to check the valves when I went for a ride today. I felt the bike washing out in the corners and it hit me! I went to my local gas station with an automatic air pump, where you set the PSI and it fills it in stages. The back tire had 6psi!!! After topping it off and the front at 36psi, I took it for a 40 block cruise. Boy did I miss being able to pass cars in a 45MPH Zone!!! Wow, I live in Tampa Bay, Florida and we have had many Thunder Storms in the last two weeks. The last air pump I used was an old school one at another gas station and I bet it was reading wrong also... With a slight decline and the wind at my back, I ran almost 60MPH for 30 blocks and the speed daemons in their cars were following me to cut traffic...

    Long story short always check the simplest answer first to any problem and always check your Air Pressure!!!

-Shane

[Alleyoop]

Those are KM/H not mph, so if the needle says 60 your doing around 35mph. That has a 139QMB motor in it , those scooter do not go that fast EVEN a 150cc will not do 60mph.
Alleyoop

[Alleyoop]

Sorry to be the bearer of facts but those are KM/H not mph, so if the needle says 60 your doing around 35mph. That has a 139QMB motor in it. To get them to do TRUE 40mph at least a 72cc BBK has to be put in. Those scooter do not go that fast EVEN a 150cc will not do 60mph.
Alleyoop

[hitshane]

The needle goes past the 80km/h (50mph) all the way to the left turn signal indicator. I am passing cars in the 45mph zone. I will see if I can make a mount, for a camera, and record the speedo and my relation of speed verse traffic. I'll take my Tom Tom with also, for speed verification. I bought this new from a large motorcycle dealership, so I don't actually know what the engine size is, as they sell several size BBK's installed. I originally wanted a red one, but they couldn't get the VIN number to work with the DMV in their computer, so they ended up selling me the blue one. Maybe I got more than I paid for? It hits 30 (same speed as traffic on a local road) in about 12 seconds. Watching several videos with 50cc enthusiasts, it took them around 17-18 seconds to do 0-30 run. I weight 200Lbs. I ordered a torque wrench. When it gets here I'll pull her apart and measure the piston!

Edit: I was able to do a couple runs though I was only able to get the needle just past the 80km/h mark. I used a GPS/Speedometer app on my Cell phone and my wife following me in her car with her Tom Tom on aswell. The wind was working against me, (Florida Weather) but I was able to hit 45MPH twice in a short distance. I will do a few more runs maybe tomorrow when its less windy.

Edit2: The scooter's stock Speedo was accurate until 30MPH, and after that anything faster was not. It was showing just over max reading, while the GPS said 45MPH.

-Shane

[Bashan]

Well thanks for the PSI tip. Let me emphasize to you that you do not need a torque wrench to set the valves. A 9mm box end wrench, needle nose pliers, and a feeler gauge will work just fine.