acceleration: Tappets or Gearbox?

Hey all, I have a 91 Civic 1.3DX Sing Carb, over the past while i have noticed a ticking noise coming from the engine, i brought it to the garage and they said the tappets need adjusting, recently it has become more noticable, i hear a similar noise when i am accelerating and recently it seems that acceleration is slower, there is a new clutch in the car so it cant be that but gear changes are still knotchy unless ive been driving in 5th for awhile and go to change and it seems ok, could it be the tappets or the gearbox? The car had a service 100miles just usual air filter, oil change and tune

well, does it tick in neutral? like when its idling, does it still make the noise?

yea it ticks in neutral its more noticable when the engine is cold, another thing about the gear box is if i come from a main road where i can go faster and then arrive in the city and start changing gears its ok at the start but it becomes more and more difficult but if i go back out on a main road at higher speeds and then change later it seems ok again, could that problem be to do with oil not getting places or something? but this acceleration thing is still annoying me

When your car is in neutral your transmission isnt doing a thing, no gears are turning, or bearings, or anything (well except for the pilot bearing but that wouldnt make a tapping noise) i'd have to agree with your local garage and say get your tappets adjusted.

Well thats what the question was, is it possible that the tappets being out of adjustment could be slowing down my car's acceleration?