What plastic material is the fuel tank made of?

[stay_upright]

The lower clear part of my fuel tank has sagged down from the top plastic bit - it's still sealed fine but stops me rotating the carb to change jets.

I wanted to glue the 2 halves back together - the glue I was thinking of 151 clear glue says not recommended for polythene, polyethelne, polypropoline. Will it be OK to glue the tank?

It does say if in doubt test on a small area first - I can try that, not too sure what i'm looking for though?

 

[gasgasman]

Use a heat gun to heat up the offending area and push it in.

A plastic welder may work on the two halves.