Thank you Didier for the measurement
( i think my Jet-1A retract its ok with some extra work . )

here is some parts for my baby :

5 servos hitec 7985 mg 12 kg for aile-flap-rudd total weight 300 gr.
2 servos JR 3421 mg 6 kg for elevator total weight 63 gr.
1 servo hitec 5645 mg 10 kg for nose gear total weight 60 gr.
1 turbine evo jet 90 9 kg thrust weight only the turbine 950 gr. ( full weight is 1400 with all accessories inc. battery )
1 powerbox competition with switch total weight 136 gr.
1 full set landing gear JET-1A total weight 1030 gr
1 receiver JR plus 3 remote receivers total weight 30 gr.
2 lipo battery 7.4v 20c 2250 mAh total weight 240 gr.
1 air accessories battle tank , valves , tubing etc. total weight 200 gr.
1 airtrap bvm total weight 60 gr.
various accessories 200 gr.

total weight for all this things is 3720 plus the viper weight 4503 total only 8.2 kg .

dont forget the painting 400-800 gr.

if the total empty viper weight is 9-10 kg its really verry good jet.