Yorkshire rider Gary Firth was killed on Friday during the Senior race at the Manx Grand Prix, casting a shadow over the final day of the event.
The 50-year-old came off at the 11th Milestone on the Mountain Course around 1.45pm and the race was red-flagged.
Mr Firth, from Barnsley, was a newcomer and had finished in 34th place in the Newcomers race earlier in the week.
Two other riders involved in the incident escaped unhurt.
In a separate incident Alun Thomas crashed at Alpine Cottage and was taken by helicopter to hospital where he was reported to have ‘multiple fractures’ but is in a stable condition.
A statement issued by the organisers said: “The Manx Motor Cycle Club wish to pass on their deepest sympathy to Gary’s family and friends.
“The Coroner of Inquests has been informed and an investigation into the circumstances of the accident is underway.”
The Senior Manx Grand Prix was won by Andy Soar, who led the race at the end of the second lap.
The result was declared after the red flags came out on lap three, with Loughborough rider Soar taking the win from Michael Moulai with Rob Hodson claiming the final podium place.
All three riders, who were contesting the lead when the race was red flagged, said their thoughts were with those involved in the earlier accidents.
Skerries rider Andy Farrell finished in sixth place.
The Manx Grand Prix reunion parade was cancelled as a result of the fatal accident.