GSUK

Hi Can anyone help. I have a Montesa Cota 247 (Oct 1973 i believe) that i have had for about 18 months now that was in a bit of a state when i bought it. Its my intention to make it look a little more like it did when it was born. When i purchased it i spent a couple of hours to see if it would run and low and behold it eventually fired up and sounded really nice ( if you like the sound of these machines that is) I rode it and it seemed quite strong all the gears worked and it seemed like it was more of a cosmetic rather than mechanical rebuild. I thought i was on the last stages after spending a fortune on parts that are very expensive for what they are and got to the stage now where the bike is 95% complete. Wheels re-spoked, frame repainted new bearings, bushes you all know the score, tank repainted and new decals. I have cleaned the carb and when i tried to start it the kick start will now not engage? That is my problem - it was okay when i got the bike and have not done anything to my knowledge that would cause this issue. Clutch seems set up correctly and oil level seems okay. Can anybody help with suggestions please. i will post a picture when i can. thanks in advance