Chainsaw problem

Dynamite it

 

Sounds like fuel supply problem if it dies when revved. Air leak maybe? Fuel pump?

 

Usually there is a filter attached to end of a small length of fuel hose within fuel tank, can become blocked, or this hose can split, so fuel never leave the fuel tank, it is drawn up a few inches before exiting in split back into fuel tank.
See it a lot on strimmers/brushcutters.

This what it can look like.

 

agree with KIAB esp if you've put a new carb on and have exactly the same symptoms

 

Send it to Pres' Trump, his Chinese mate will help you out.

any ideas. Could be a faulty carb, just like the original one??

When running spray some WD40 around the carb & intake area. If you have an air leak the WD40 will show it up.
It will alter the running. Will need another person to spray for you, but make sure you have gloves on, & water close bye.
Not for the faint hearted.
WD 40 is flammable.

 

For heaven's sake. New spark plug!

 

I thought op had mentioned he replaced it, but rereading his post he didn't.

 

it starts ok, when the plug is under most pressure, but dies when revved.

Normal reason for dying then is too little, or too much, petrol

 

Is the fuel fresh? It doesn't have a great shelf life which may be causing some issues.

 

When you start it, will it tick over by its self on and off choke.

 

Well you've covered most things, the only real thing left that could cause the problem is lack of compression, this is quite common on cheap Chinese engines, they wear very quickly.

 

Or weak spark!

 

This month old petrol, was it pre mixed a month ago.

 

Spark plug. Put a new one in, and be careful with your new machine!

Spark plug has to work much harder when revved. Weak spark will idle, but flood and stop when revved.