bike starts up as normal but as soon as the throttle is opened up the revs die and the bike wont go anywhere. this is now causing some issues as i am back on taxi duties. All the obvious faults have been explored to no avail with a mechanic. Has anyone got any ideas please?

John in Jersey, May 2010

Many thanks to all who answered. the bike was taken back to the dealership. eventually the CDI was swapped out and hey presto its back up and running again.

john in jersey, May 2010

hi john,really your mechanic should be able to fix this problem is he a proper motorcycle mechanic?or a car mechanic?its without a doubt a weak fuel problem.if you take the slide out of the carb from the top by undoing the diaphragm cap then you can take the spring and slide out,then take the needle out of the slide and see if it has a small eclip on it if so then move the clip to the slot nearest the pointed end of the needle and re assemble it and try it.also drain the carb fron the drain screw at the bottom and see if it has any water in it.

adam bike doctor, May 2010

many thanks guys. most of this has been explored by a mechanic. he has also checked the electrics and all seems to be as it should be. will pass on your thoughts though. i think the bike is a four stroke

john in jersey, May 2010

4 stroke or 2 stroke?

m, May 2010

if it dies as soon as you open the throttle then the bike is running weak(too much air to the fuel/air mix),there is either a problem with the carburettor jetting i.e a blocked jet or the air filter may have either come unattached from the back of the carb or it may have a leak elswhere and this will cause an excessive amount of air to get into the engine and upset the fuel/air balance.also there may be water in the fuel.take off the carburettor ceqan it righ out and make sure all the jets are clear dont lose the choke jet as these are just pushed into the float bowl and will pop out at 1000mph if you use an airline on it.take not of whether the fuel has water in it or not it will be at the very bottom of the float bowl on the carb.check the vaccum tap is working as it should too it should allow fuel to flow when a vaccum is pulled on it .

adam bike doctor, May 2010

Please see my answer in the car section, thanks.

crabbiepattie, May 2010