A Perth motorcyclist has been fined $550 and 4 demerit points for a loose chin-strap on his helmet, which he says he started to undo while talking to the officer.

Julian Collis was going through Malaga when he was pulled over by two police officers.

“Initially when he first pulled me over I was going to completely remove my helmet so I’ve loosened my chin strap to talk to him, but I’ve actually just lifted my visor,” Mr Collis said.

The man was fined $550 and four demerit points. (Supplied)

Julian Collis said he loosened his chin strap to talk to the officer. (9NEWS) (9news)

“I didn’t think I’d be there for long because I hadn’t been speeding.

“He was going over my bike and having a look around, seemed like he was trying to nitpick at it but he couldn’t seem to find it.

“That’s when his colleague came over and explains that my chin-strap is too loose.”

Mr Collis said he couldn't afford to pay the fine. (9NEWS) (9news)

He said he wasn't speeding and wasn't sure why he was pulled over. (9NEWS) (9news)

The father-of-three has written to police to question the fine. (9NEWS) (9news)

He thought the fine would be a minor infringement but was shocked to learn how much he had to pay.

He said he could not afford to pay the fine.

The father of three said he will challenge the fine with the police.