Taking to Facebook to vent his frustration, Liam branded the different treatment as "racism at work in Britain", urging people to share it so as to not "let them get away with it".
The post quickly went viral with more than 6,000 likes, comments and shares.
The shop to which the Shell garage is attached have claimed they believe the woman was wearing a hijab - which is open face in the same way that Liam's helmet is - however both Shell and Spar have yet to comment on the row.
"And yet there was a lady there wearing a burka filling up.
"I could understand it if I was there with a full face helmet on, on a dodgy looking bike, sat there on the back with the engine running while filling up - could totally understand that.
"But not when I have put thousands of pounds through that station over the years. I have not been asked to remove my helmet before."
Liam, who was riding his Yamaha Tracer 900 bike, claims it was the first time he has ever been asked to remove his helmet while filling up in all his three years as an instructor.
After the years of loyal custom to the garage, Liam claims he and his other instructors will now be buying their petrol elsewhere.
Liam said: "I don't want to pursue it any further but I won't be returning to that garage again."
Liam's post sparked a heated debate over whether the garage's request was racist or not, which he refused to be drawn into.
His original post read: "Bikers avoid Three Arches Shell filling station Blackburn.
"Told to remove my helmet when filling mine and students bikes. I was wearing a flip front white helmet in the up position and my company name all over mine & students hi viz jackets.
"Mean while an Asian wearing a burka was allowed to fill up her car.
"Racism at work in Britain. Please share this. Don't let them get away with it."
Shell has declined to comment about the incident when approached by MailOnline.
