[drtung]

symptom: The first thickest section of the mast does not retract.

Remove mast - unbolt the top screw at the base of the mast. Switch on radio and quickly got to the back and pull the whole mast out.

Examine- any loss teeth on the nylon white strap. Spray lots of silicone into the mast. Hit the mast on the ground till the unretracted portion get into. repeat lunbrication and rotate the section till it gets smooth to retract.

Reinsert mast with teeth pointing bottom. Switch off radio and the gear with catch the nylon strap. Retraction complete and tighten the screw.

It should take less than 10mins. But the red straw on the silicone can sprayer dropped into motor "black hole" accidentally and I need to dissemble the whole thing. And found the gear/ motor inside was all filled with firts and soots. Clean it and re-lubricate that with grease. The motor now sounds complete silence.