Atco ensign b14 tk carburettor.

Hello

I have a Atco Ensign with the 114cc aluminium engine. It is fitted with the TK carburettor. I have cleaned and rebuild the carburettor as I have just bought this mower as a non runner.

The mower is running now. But the engine goes from idle with a small movement of the throttle to very high revs. The engine to me is very noisy sounding much like a high performance motor bike. It seems to run well. The silencer is in good condition. 

My question is is this normal for this carburettor? I have other mowers with this engine with the Italian carburetor begin with a d dellroto? These run much quieter and do not rev as high.

I am worried due to the noise as it will annoy my neighbours. I wondered if something is wrong with the carburettor. 

Thank you for your help

Rob