sym jet euro 50x wont start ?

been working on my mates bike and its in a bit of a sorry state , its done 4000 miles and is having running problems we fixed it a while ago when we took the exhaust off ran it and put it back on but then my mate tried to wheelie and it cut out and he nearly fell off :L since then it hasnt run , need help soon as im working on the bike on sunday and need to know how to fix the problem

 

really need a solution :/

 

sell it and get something decent :/

 

its not mine and my mate is a cheap skate

 

what exactly have you done to it? when you say you worked on it, what have you been working on??

 

well just taking it apart trying to find out the problem

 

You took the exhaust off and it worked so you put the exhaust back on?

Deosn't that tell you the problem lies with the exhaust

 

well the exhaust went back on and it worked then he wheelied and it cut out and there is fluid coming out of the exhaust hole :/

 

sounds like it's just flooded the crankcase to me?? probably just coinsidense that you removed the exhaust??

 

its like a blacky liquid , and we have left the bike for like 2 months so it should be all good in the crank case and everything , i really dunno :/ the restrictor pipe isnt crimped properly so there is just a hole there could that affect it ??