i have an 85 tri-z250 that has a prob.it will fire up & run if you pour gas in the cylinder.also we pressurized the gas tank with an air compressor n it ran for a minute n died.all the fuel lines and carb are clear.jetting is ok,ignition is okplug is new n gapped.anyone know about the fuel pumps that were on these models??? thanx
dont know that particular modle but most are a vacume operated pump.
i would start by checking the vacume hose to the intake. then i would check the
pump itself, it may be packed full of crud or have a tear in the diafraghm.
also check youre cap and make shure it is venting, if it sucks the tank to a
slight vacume the pump cant pump.