John was probably the son of Edmund Spinks and Sarah Crick and baptised 3 July 1785 at Rushbrooke. He was 5 feet 7 inches (170 cm) tall, of pale complexion with light brown hair and hazel eyes.

In 1813, with John Garrod, Charles Nunn and John Haywood, he was convicted of a burglary in the house of Mr Philip Steggle of Wickham Skeith. All were convicted and sentenced to hang but were reprieved before the judge left town.

From a hulk at Woolwich, John, with 123 other convicts was transferred to the General Hewitt. The ship called at Sheerness and Portsmouth to make up her complement of 300 convicts. She sailed from England on 26^th August. The convicts transferred at Woolwich had been confined below deck for 27 days.

About three weeks after the start of the voyage, dysentery broke out and within a fortnight after leaving Madeira twelve to fourteen convicts had died. Three weeks prior to their arrival in Rio de Janeiro, a sudden squall drenched the convicts bedding which was on deck while the prison was being fumigated. Rain continued and the bedding could not be dried, so was thrown overboard. By the time the ship made Rio de Janeiro a great number were ill with dysentery.

From the start of the voyage, two days each week were appointed for shaving and cleaning the convicts, but this was not persisted with. They were, however, obliged to appear clean every Sunday on the quarter deck, in order to attend divine service. Once the ship arrived in Rio de Janeiro, the convicts became exceedingly filthy. There was no fresh water allowed for washing their linen and the allowance of water was reduced to three pints per man per day. About twelve ounces of soap (340g) was issued once a month to each mess of six men.

General Hewitt anchored in Port Jackson between 12 and 1 p.m. on 7 Feb 1814. Thirty four convicts had died during the voyage. Most had died of dysentery but four died of typhus, two died of apoplexy, two of remitting fevers and two of extreme debility without apparent disease.

By 1822 John Spinks was a landholder with a ticket of leave. He was a tenant farmer in the Illawarra in 1828, was conditionally pardoned in 1832-33 and spent at least the last 18 years of his life at Jamberoo in NSW.