tbh... if your using vinegar.

Careful it may only be weak acetic (ethanoic) acid but I remember doing experiments with that stuff in school at GCSE. It will eat the magnesium.

Make sure you swill any solution out well afterwards with water.

Oxalic acid is the bigger brother of acetic acid basically. Two -OH groups as opposed to acetics one.

Its more reactive, and if its concentrated stuff and not diluted expect it to eat away the magnesium in a shorter time Careful with it!

Well the magnisium is in the cylinders and was added to lessen the weigt but they added a bit to much the rads are detached so I guess there will be no problem.

Ahhhhh right lol I thought you said the radiator was made of magnesium or something lol! meh.. if its aluminum, its unlikely to be rust then like you said... probably the gunk!

even though the cylenders are magnesium lined for a guess, the actual block its cooling and the channels the coolant run through will still most likely be cast aluminum.

whats had the leaks?
the engine or the rad?

Quote from: madmaxeven though the cylenders are magnesium lined for a guess, the actual block its cooling and the channels the coolant run through will still most likely be cast aluminum.

whats had the leaks?
the engine or the rad?

The engine which is now fine everthing is in good shape now he is ready to go
except rads, he will put on couple of smaller ones for an similar 2 stroke untill
he gets these sorted.

is it thick and hard ? or goo/goopy ?

steam cleaner / hose pipe / etc... would help it out a bit

steam cleaner would be good