@ Mjuaji, hata mimi nilikuwa na shida kama hiyo. It started right after a service so I changed plugs several times lakini wapi... problem persisted.
If the plug wires are faulty, try pulling out and returning each plug wire one by one. As you pull them out, the vibrations will worsen and reduce when you put it back in. If you pull out a wire and vibrations remain the same or change very little compared to the others, that lead wire may be faulty.
trick 2, clean out the throttle manifold. Remove all the soot build up that occurs in that area and around the throttle valves. This helped my shida quite a bit lakini it did not go away completly.
trick 3 - jaza tank ya petroli halafu weka mkebe moja ya petrol fuel injector cleaner. Did this once.Hiyo ilinisort kabisa. Sasa vibrations ni kidogo sana when I start up in the morning.
They must find it difficult....... those who have taken authority as the truth, rather than truth as the authority. -G. Massey.