ls 650 from 1988 with 28800 km. (19.000 mp) on the clock

Bought the bike last year, but did not touch the motor, just did the obvious  - brakes cables etc .

Just filled the tank with fresh gasoline, went to the Beach about 15 km away: At the ride home bike started  to act up. Would not "take the gas", but stalled & backfired. At idle it died, after a little while, it was able to start after a lot of trying, but only in idle mode and very uneven  it was. Trying  to rev the bike the engine died.

After 2 mins more waiting. I could start it , so i could hump home.

I wonder if this behaviour is gasoline or air related , or both

What do You gurus think ?  

And if you dont know the cam chain has been serviced, either a Versy installed or chain replaced, you need to look in there RIGHT NOW... cuz the miles on it are well into the range where the tensioner spits its guts out & destroys the engine,, & by destroys I mean ruins it. It will cost more to repair than buying a used one, paying freight & swapping cost,.

I would listen closely to that engine & if I had even the slightest doubt, Id open it up.. Snot hard,, time consuming, but not demanding of mechanical ability to any real degree, UNless it needs a chain, then it gets a little challenging, but theres enough people here who know how to talk a rank amateur thru it,, & the cost of tools  to do it is nothing compared to the cost of paying to have it done,