It's The Cisco Kid

I picked up an old VHS tape of Viking Classics 1986 that is Vol 1 of The Cisco Kid starring Duncan Renaldo and Leo Carrillo. There were two episodes: The Quarter Horse and The Postmaster. I liked The Quarter Horse more than the Postmaster, but they were both worth watching just to refresh my memory of this duo. In the lat 1940's, Duncan Renaldo and Leo Carrillo carried on the tradition, making five movies and there was a TV series that followed.

This tape is of the TV series in black and white and the Kid is wearing the flashy suit. In The Quarter Horse, a race is rigged to cheat a quarter horse rancher out of his holdings. There were actually two races between a thoroughbred and a quarter horse. The quarter horse won the first which was only a quarter-mile, and it won the second, too, but it was longer race wherein there were four quarter horses and one thoroughbred running a mile this time. Anyway there were shenanigans in both and The Cisco Kid and Pancho get mixed up in it and, of course, catch the bad guys.

In The Postmaster, Pancho urges Cisco not to go into town because every time he did, he got them into trouble, and this was no exception. The Sheriff throws Cisco in jail for suspicion of murdering the Postal Inspector who had come to town to investigate a band of outlaws who were stealing the mail. After escaping from jail, the duo solve the mystery of the unknown killer and the means of concealing his weapon.

More info can be found at Wikipedia on the whole story of The Cisco Kid and the movies.