There can be many reasons for a burning sensation and inconsistent/irregular flow while urinating, including these:

-sexually transmitted diseases
-infections and other conditions involving the urethra, bladder, or even kidneys
-alcohol abuse
-caffeine
-dehydration
-enlarged prostate
-and many more

Many older men experience "urinary hesitancy" caused by enlarged prostate glands, according to the NCBI of the National Institutes of Health:

http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=adam&part=A003143

That link includes helpful information on urinary difficulties and offers these home-care pointers:

-Monitor, record, and report your urination patterns to your doctor.
-Apply heat to your lower abdomen (below your belly button and above the pubic bone). This is where the bladder lies. The heat relaxes muscles and aids urination.
-Massage or place light pressure over your bladder to stimulate emptying.
-Drink plenty of fluid
-For infections, antibiotics from your doctor will be needed. Symptoms that suggest a possible infection include burning or pain with urination, frequent urination, cloudy urine, and a sense of urgency (strong, sudden urge to urinate).
-Pay close attention to any medicines or supplements you take.

The condition you describe, though, is definitely worth a consult with your physician. The visit will be most helpful if you bring with you some of the monitoring information suggested above

I hope this helps.