Basically when

I brake and slow down my bike sounds like a clunking coming from the front part of the engine

Ybr 125 2 years old

Any ideas why this is happening or how to fix it

Any help is welcome

Go for the basics first, are the engine mounting bolts tight? Just whack a spanner on them and test to see if they are tight, is it in fact the engine the noise is coming from? look at your forks and the bits that are bolted to them. Really you need to be a bit more specific as to exactly where the noise is coming from, I know it's not always easy to figure these things out but just saying "I have a rattle at the front" is not a lot of use.

I assume your a fairly new rider and as such some of the things we say might be a bit strange to you but don't despair all will be sorted if you can make your questions a precise as possible, by the way WELCOME to the YOC it's always nice to have new folks join in.

Hi

Are you sure the ‘clunking’ is from the front of the engine, if so

Are the engine mount bolts tight, including the top one if your bike has one?

Are all the component parts that are attached to the frame/chassis securely attached tight?

Has anything worked loose?

Clunking from the front of a bike in my experience bike is normally associated with brake callipers being loose, worn poorly adjusted steering head or wheel bearings, play in the front suspension bottoming out worn internals, handle bars loose, or a loose exhaust.

Also worn chain sets/ suspension linkages can give funny clunking noises as bikes come to a stop.

If it was my bike I would give the bike a real thorough clean, top to bottom hands and knees and check and clean every linkage and every visible nut and bolt, and if you can remove the tank, seat, side panels and other easily owner removable components to examine the bike,

Hopefully you will find the mysterious noise,