my daughter has a 2007 sukida 50cc moped, it has had a new battery, new spark plug, new ignition switch, the carb has been cleaned and fuel pipes replaced as it has sat unused for the last year. It starts but has very little power and only runs about 100 yards or so before cutting out! she's been told that she may need a new carb? also been told that she has to put oil in the petrol tank, is this correct?????

desperate bob :o(, August 2010

Thanks for your suggestions guys
Have had the valves checked and adjusted but problem remains the same, still no change to the original problem!
Has anyone got any other suggestions or ideas other than a new carburettor??????

desperate bob :0(, August 2010

i agree with the boys sounds like tight valve clearances!!!!

m, August 2010

As bb says that is definately a valve problem,i would bet your bottom dollar its the exhaust valve tight. if you take the panel out at the front of the seat(just under it) and undo the 4 8mm headed 6mm threaded bolts from the rocker cover then pull the rocker cover off and then push the kickstart lever down gently until you see the inlet(one at the top)push down then the next up ward stroke of the piston is the compression stroke,on this stroke you need to check the clearances of the tappets and set the with a feeler guage to .05 on the inlet valve and .08 on the exhaust

adam bike doctor, August 2010

NO!! DONT DO IT!!
Is this a 4 stroke or two stroke. All modern engines are four stroke.
If it is four stroke you dont need to put oil anywhere, except keep an eye on the oil in the engine. DONT put anything in petrol. If you have you need to flush system out. Drain tank empty carb etc. If you are going to put something in the fuel then it needs to be redex or similar. This can clear dirty carbs.
These Chinese bikes use soft metals.
It could be one of two things.
As you say the carb or if it is four stroke, which it probabaly is, then the valves tighten up and as a result you wil have problems starting and running.
I would get valves adjusted first. As Adam who comes on here quite a bit and is a bike mechanic by trade says this is a very comman fault. You will need a manula to be able to do this properly
Good Luck

bb, August 2010