Honda City 2004 RPM goes 0 During Gear change or release the race in traffic etc

[musman.saleem89]

Mere pas honda city 2004 ha kbi kbi smooth chalty hovay jb race choro clutch daba k for gear change ya traffic wagera mei tu band ho jati ha.. please guide regarding this issue i shall be very thank full to much experts opinion required.
Thanks

[muhammad.talha3001]

Check condition of spark plugs. This particular model has 8 spark plugs, unlike the usual 4 found in cars of this engine size. People usually the change the first 4, but forget to change the last 4.