Rear Cylinders Not Firing

[BurntCastor]

New member here with recently aquired 85 RZ500N. Bike was sitting for some time without running. Seller said it ran fine recently but he was not telling the truth (whole other long story). So i put fresh fuel and 2t oil in it. Bled oil pump. Started right up on the choke but rear cylinders wont keep running. Bike will not run without the choke. Can't ride it obviously with two cylinders out. Checked fuel lines, petcock - carbs definitely getting fuel. Fuel line does not have air pockets of air bubbbles - solid fuel. Spark is strong. Rear plugs are not getting carboned up. But there is oil or fuel on them (they are not dry). Im guessing either the pilot jets and/or air jets are clogged and possibly the needle & seat stuck closed or clogged. Any other ideas? Why would it be just the rear cylinders - random deal or is there a reason it would be only the rears? Front cylinders seem to be running strong. Bike is mostly stock except for JM pipes, pods and a capacitor in place of the battery. Thanks.

[WVWRZ500N]

New member here with recently aquired 85 RZ500N. Bike was sitting for some time without running. Seller said it ran fine recently but he was not telling the truth (whole other long story). So i put fresh fuel and 2t oil in it. Bled oil pump. Started right up on the choke but rear cylinders wont keep running. Bike will not run without the choke. Can't ride it obviously with two cylinders out. Checked fuel lines, petcock - carbs definitely getting fuel. Fuel line does not have air pockets of air bubbbles - solid fuel. Spark is strong. Rear plugs are not getting carboned up. But there is oil or fuel on them (they are not dry). Im guessing either the pilot jets and/or air jets are clogged and possibly the needle & seat stuck closed or clogged. Any other ideas? Why would it be just the rear cylinders - random deal or is there a reason it would be only the rears? Front cylinders seem to be running strong. Bike is mostly stock except for JM pipes, pods and a capacitor in place of the battery. Thanks.

99 times out of 100 if the cylinders only run on the choke the pilot circuit is blocked off. Will require removal and cleaning of each carb to be sure.

[BurntCastor]

On the VM26ss jets same as all round slid Mikuni? 4/042 large hex mains, vm22/210 pilots, VM28/86 needle jets, vm26-26 needle&seat, #5 jet needles?

[vdrive]

how long was the bike sitting ?

[BurntCastor]

Problem solved. Found pilot jets loose (finger tight) in upper cylinder carbs. Very odd. PO wasn't Mr. goodwrench. Runs great now. 220 mains, 25 pilots, stock air jet are about perfect with pods on the ears and JM chambers at sea level.