i hear a rattling noise in the carb (top part) and there is no pertol in the hose leading upto the carb i brought it back from m.o.t perfectly well.. after 2 days it doesnt start no more ,
no parts are missing no connections are loose i was just about to go legit on the bike
everything else works lights horn e.t.c
it makes the same noise when i try 2 start it with the spark plug in and when i take it off
please can anyone help????
thanks

mark, June 2010

i think its the fuel petrol tap stoppin the fuel from going into the carb, im not sure .... i opened the carb and its fine and the rocker arm is good, thanks
let me no what you think ,

mark, June 2010

when you say the top of the carb is rattling do you mean its loose as it should be bolted on with some little screws,if it is loose then the slide will not lift up under throttle as it relys on a vaccum in there to lift it and any air leak will loose the vaccum.i have got 3 dna 125 carbs so let me know if you need one.if the petrol light is on then the fuel level is low or the sender is faulty so fill it up and there should be petrol visible in the fuel pile so thats another indication theres no fuel in it.a dna has a pneumatic fuel pump and also a one way valve in the fuel line.the head is the part that the spark plug is bolted into.you really need to make sure the rattling noise is coming from the carb its not a common problem but if it is loose it wont run right for sure,if you take the spark plug out put the end of your finger in the hole in the head and turn the engine over does it blow you finger off with alot of force or can you hold it there?these 4 valve leader engines drop valves lets just hope it has not done that.or it will be afair few quid to fix it.

adam bike doctor, June 2010

reply to bb,
there is no petrol in the cables coming form the petrol tank into the carb , the top part of the carb (round metal part) is rattling as stated before,
i dont no what a head is ' (maybe the top part of the carb?)
i checked the plug and its good ,petrol light showin as soon as i turn it on and stays on....
but the bike wont start im thinking to take it to a mechanic ????? or should i buy a new carb?
and i dont no what roker arms are either ?
can the engine be flooded ?? or siezed ?
thanks again

mark reply to (bb), June 2010

roker arms are very weak in these bikes! I know this cause ABD tells me. Are you sure its your carb and not your head? Roker Arms sit in the head of the cylinder.

I cant think of any reason why your carb would rattle but take apart and have a look. Something may be loose.

Alas if it is your roker arm its a top end strip.

bb, June 2010