have you cleaned your air filter - if it's dirty / clogged, etc it would make a difference. Likewise if it; wet it will not start.do you leave your fuel tap on the on positionf ro a long time? If so, it could flood the carb,
so swithc fuel off, choke off, throttle off, and kick / start it over, the fuel int eh carbs will work their way through, unflooding them, then it'll start, so put the fule to on and remember not to leave it on.

this is really common with dirtbike style bikes, which your TDR is a derivative of the DT125R