The owner told me that its 37000 km and is with new oil
Wait a fewking minute here!!! Shouldnt that sentence read "told me that its
HAD its 37000km
SERVICE & is with new oil" as in, its been to a STEALERSHIP for a tune up?!!????
OK, PULL the tank.....
check for disconnected vacuum hoses, unplugged connecters, etc.... carbs may b fucked up, check if they are synch'ed right, the timing may be off as well.....go over the entire thing... were the valves adjusted by some Chumly on his 1st year apprenticeship? Find out where the PO took it too, find out what they did EXACTLY, BE NICE, and NEVER go to that place again.
Beers ago this happened to a Buddy of mine. after 1300 miles over 3 days of riding his new Harley wouldnt start after gassing it up, to the point, that we ended up getting a motel room right there & wait for the local dealership to open up. 3 beers and 1 joint later I found out by asking if he just had new aftermarket pipes installed on the bike before he picked it up. I asked him if they re-jetted the carbs, and when he said yes, I was walking out the room to his bike to check his vacuum petcock lines. Sure enough 1 had disconnected. Plugged it back in, bike started right up purring like a kitten.
ZX-11s will also run w/o a fuel pump, but poorly, so make sure its plugged in as well.