Last season
 

Ok guys last season the bike runs well ,now when i open the throttle he lose power and than increase it when is hot seems better some reason carb cleaning or smthn with the petcock?

How long did your bike sit idle? Did you treat the fuel in your tank with Stabil or another gas treatment product? It could be shellac build-up in your fuel system.

I like to run Seafoam in my fuel about every 6 months or so now that my GZ is no longer my daily rider. 1 oz. per gallon capacity. It keeps everything squeaky clean.

You might have sediment on the inlet screen of your petcock or build-up behind the diaphragm. Options : drain tank, check petcock inlet, take petcock apart and clean, and if all else fails, clean carburetor.

Hi again , yea i use stabilizators also a high octane fuel, i will check again because a snow fell here again, but i think the air fuel mixture is too lean , because when i open throtle , it seems bad acceleration ! Could it be a reason? On idle and on low rps with smooth throttle open is ok than max throttle and goes bad?

It could be a stuck float. Also, you might want to start it up and run it with the petcock set on prime to see if that makes a difference. I would think that would determine if the diaphragm in the petcock is bad. Worth a try.

Clean the carb it takes 30 minutes. Sheesh.