Hello Sake, welcome to the forums. where are you and the bike the US? There really isn't enough info to go on in just that pic. more and closer pics may help. just a quick glance I could only narrow it down to '83 to 87ish jusdging by the decal style (and the DT one looks to have been replaced)
Can you get some info on the tubing type and the model of Suntour? maybe the cranks and brakes?
If this is a US market bike the fork could be a replacement, so i would check the headtube area for possible damage.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk