The Suzuki RG 125 was launched 1978, simultanously with RG 185, formerly knows as GT 125 and GT 185 with new paint jobs. Neverthelsess, the RG 125 was still sold in some countries with its old name, GT 125. In some countries the model was known as X4. The RG 125 didn't have the Ram-Air cylinder head of the older GT 125.