Motor revs fine on my kawasaki 400 but try to ride and it dies anybody know problem this is a 1989 zxr

Also check the side stand switch disconnect it

Being a 4 stroke 1st thing to look for is spark plugs.Get them checked properly.Its the most likely problem.Next.Water in the fuel.1 litre of metho to 20 litres of fuel.Drain the bottom of the carbies 1st then check what drains out.A bit of **** in a jet will also make the bike play up.Rev the bike to above 6000 revs,slam the choke on and off 2 -3 times.Because the air is rushing into the engine at a huge rate,the choke will stop this and only let fuel in.It SOMETIMES clears a blocked jet.Mate.I hope this helps