Changing the muffler often does wonders to the power of a scooter. So does getting a different carb. Your local shop can help you there or call around.

Check the cable on your speedo before diving into sensors. Is it really connected? A lot of times its the simple solution that is overlooked.

1)
If this bike indeed has a 4-stoke engine, then you use an oil like 10W-40, and it goes in the engine. You check the level either by sight glass or dipsick.

2)
Many 50cc and less scooters/mopeds have restrictions to reduce top speed. Such restrictions can be found on the variator, in the exhaust system, or the fuel delievery system.
I would recommend removing any such restrictions before you start spending money on hot rod parts for your scooter.
Once this is done, you may find that you bike goes fast enough.

However, on the off chance that the “70″ in the model name means 70cc(because it does not mean hoursepower), then you most likely don’t have to worry about restrictions.

3)
Pull the speedometer cable off of the back of the speedometer and turn the front wheel. If the little piece of metal turns in the cable, replace the speedometer unit on the handlebars. If the little piece of metal does not turn, replace the speedometer cable. Sometimes the problem is in the hub. A plastic gear can break in there, but most of the time it is just a snapped cable.

Fuel gauges usually have problems of an electical type. Check and make sure all of the connections are good on the tank, on the gauge, and eveywhere in between. Most of the time you will find an odball wire that has come loose, and that will be the problem.

Finding parts for the bike may be difficult to find. I found a link listed below for your bike, but nothing on parts. Support may be hard to come by if you did not buy from a local dealer.
Good luck
Ride Safe

testicles

a whooptie

… I could go on.