Have you checked the exhaust is correctly fitted and sealed? Distant memory suggests that if air is being sucked in the exhaust will pop and bang. Might be the 2 stroke fumes hallucinations mind...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
