Farmers John Helyar and his son Michael were using a tractor to move a metal windmill on a neighbour's property in Rainbow, 100 kilometres north-west of Horsham, when it clipped a 12,500-volt power line about 11.45am.

The men, aged about 60 and 35, were electrocuted as the eight-metre windmill hit the line and the tractor erupted in flames.

Two other men, father and son Ian and Nathan Wheeler, believed to be in their 60s and 30s, made their way to the Rainbow-Nhill Road with serious burns to their legs.

They were flown to The Alfred hospital and were in a stable condition last night.

Another man at the scene, believed to be the partner of the property's owner, suffered shock and was taken to the Jeparit Medical Centre.

Power to the area had to be switched off. Paramedics were unable to get to the scene because of the sandy terrain.

Horsham Police Service Area Inspector Colin Renton said the men were using a front-end loader to move a windmill up a hill and beside a dam and bore.

''But no one looked up,'' he said. ''Police have spoken to all the families and they are very distraught and upset.''

The Jeparit-Rainbow Lakers football club, where Michael was president, cancelled training last night and held remembrance drinks for the former player.

He was a keen horse rider who leaves a wife and two boys at primary school.

The Helyar men lived in two nearby houses on the same property on the Rainbow-Nhill Road, where they farmed grain and sheep.

Hindmarsh Shire Council mayor Michael Gawith said the men were involved in local golf and bowls and were known by everyone in the town, which has a population of about 600.

He said it appeared the men were ''just being good neighbours'' by helping move the windmill.

''The whole community will be in mourning,'' he said.

''I'm struggling to keep it together here.