'Tappetty' old engine

[Ricco1]

My GN125 is from 2006, 30,000 miles on the clock. A couple of years ago the engine developed a nasty top end noise when I was on a motorway. Not feeling too confident working on bikes myself at the time, I took it to a bike shop. The problem was a worn rocker arm, which they replaced. Ever since then there's been a slight top end rattle, best described as tappet noise. The bike shop assured me the valve clearances were checked and this noise is normal with small engines, when they've done a bit of work.

The bike has been reliable since, despite the noise. I'd quite like to get rid of it though. The noise that is. A couple of questions:

Is it normal for an older engine to become more noisy?

The valve clearance range on this bike is quite wide. Generally speaking, would a bigger or a smaller gap tend to cause more tappet noise? I guess I'm thinking along the lines of adjusting the clearance to close to the specified limit, bigger gap or smaller gap, whichever one makes the engine quieter.

Cheers for any replies.

[iangaryprice]

When they repalced the worn rocker arm there was probably other parts that were slightly owrn but not too bad.

The rocker arm is mounted on a shaft, this could be worn.

The range of valve clearance gaps genrrally allows for the difficulty of settign them precisiely.

I always make sure the minimum size feeler is loose and the maximum won't go in.

[Stu]

An engine would be quieter if the gap was smaller

But running a smaller gap you run the risk of needing adjustment sooner rather than later

you also run the risk of the valve been slightly open if the gap gets tighter which could cause poor running and burn your valve seats out

[Mississippi Bullfrog]

I'd stick with the old adage - a tappy engine is a happy engine.

Better to have sufficient clearance and a tapping than a silent engine that is burning its valves.