What spark plug does a tao tao 50 use ? My scooter is suppose to have an 88 cc big bore kit in it. What is the plug gap ?

Number of things air filter needs cleaning spark plug gap but I would try the carb air screw 2to 2half turns out from fully in count the turns as you turn it in just in case

being a 50cc engine it should have only 1 piston
If it is a 2 stroke , it will fire every time the piston comes to tdc
if it is a 4 stroke it has to have a timing point that excites the ignition system for every 4th stroke tdc
if the exciter receives a signal to fire the plug at the wrong time , it is getting that signal from a fault or incorrect timing
that fault can be
loose wire/s,worn unit that controls the timing ( distributor fault), loose flywheel , flywheel touching coil,incorrect timing (180 degrees out ) stator loose ,rotor loose,faulty crank position sensor
it is good practice to have a workshop manual on hand and if you don't have one go google and type in --workshop manual for 50 cc tao scooter--and see if there is a pdf version in english to download

May be something as simple as spark plug worn... Re gap it or replace it with a new one.

hi, that's a cable right, check where the cable goes into the wheel hub , what can happen is the cable breaks, if it 's electronic, look for the sensor on the wheel...

Regards
Rob..
www.gewizrepairs.co.uk

0.02 in (or)
0.5 mm

Here is a link to the full manual. Spark plug info is on page 50.
HOPE THIS HELPS!

David http://www.stihlusa.com/admin/webcontent/cmsfilelibrary/instructionmanuals/fs120_200_250_manual.pdf

It's a pretty big job. You need to be competent (and confident) with tools as well as diagnosing and repairing gas engines. Without knowing the details of your scooter, the overview is this: 1) Remove the carburetor (if mounted to the cylinder), exhaust pipe, cylinder head, cylinder and piston. 2) Have the cylinder bored out** to provide the correct clearance between the cylinder and the piston (if different from the scooter manufacturer's clearance this information should be provided by kit manufacturer). 3) Modify the head (more machine work to reshape the combustion chamber to work with the larger bore). 3) Reassemble. 4) Modify the fuel system (usually a carburetor) to correctly fuel the now larger displacement engine. 5) Get the new set up running and then tune it to run properly without damaging itself from an incorrect fuel mixture.

** Some cylinders are aluminum with a steel sleeve that forms the bore that piston runs in. Some are aluminum with a thin nikasil coating on the aluminum bore. These will be much more expensive to bore out as they will need to have the coating replaced after being bored out.