This has been a common problem for me on my 86 Tenere for years, give the carb a good clean out and readjust the secoundry carb, and if you have them change the fuel filters. This works for me every time. I do this every six months and have no problems.
Also check the gap on the spark plug, some thing a lot of people forget to do on fitting a new one.
And make sure the air filter is clean, if dirty this will affect the running at lower revs, but not so much when you rev the engine to pull away or at higher revs.
Hope this helps Skip
Do the best you can with what you have,
A stranger in a strange land now heading North South East West to.....