Hi all it’s been a very long time since I posted here. I had to put my bike on hold for the past year for family reasons plus I had to move which was no fun. My bike (69 DT1B) has been sitting all this time without any attention. I finally was able to get back to it and with a fresh attitude I was able to overcome the headaches and I am happy to report that the old bike is back on the road!  In fact letting it sit for all that time helped me identify what I think was the biggest problem I was having. I found a slight vacuum leak on the intake between the spacer and the head. However the big issue was micro fine rust powder in my gas tank. Very early on in my project I did a rock shake inside the gas tank. The inside cleaned up very nicely so I continued with the rest of the bike. After letting it sit for the past year I knew it would not start but I pushed it up my street and bumped it over. To my surprise it fired up but it was short lived. I pulled the carb and cleaned it out. There was a bit of brownish varnish from gas sitting in the bowl. After a thorough cleaning it started and ran. 
2 days later I could not start it. Once again I pulled the carb and cleaned it again. To my surprise the idle jet (emulsion) tube was pretty plugged up again. 
I decided to drain the old gas and put fresh gas in. That’s when I realized that, although I thoroughly cleaned the gas tank early on, I never sealed it. HUGE MISTAKE!!! I was amazed at how much rust powder was in the tank and how fine grained it was. It easily went right through a new fuel filter. 
I used a Kreem tank seal kit and now the bike fires right up every time. Finally I can go out and ride without worrying if I’ll make it back. 
my advice to anyone with an old bike is to clean and seal the fuel tank. 

Thanks to all who helped me along the way. 

Thanks for the update & keep coming back, hopefully with good news.