gpz 305 fork iol is 140 cc per leg
321cc +/- 5cc
online manual suggests 10w/40, 1.8l with filter change, 1.5l without.
1984 GPZ900R (development in 1982 - 83) and was the first Kawasaki to be marketed under the Ninja brand name in NA. Prior to that bike, most of Kawasaki standards or sport motorcycles were called GPZ. I have the 1984 900R and it has both the GPZ and Ninja names on different parts of the body.
On a Kawasaki GPZ 600R, the engine number is typically located on the right side of the engine block, near the crankcase. It can usually be found stamped into the metal, often on a flat surface for easy visibility. If you're having trouble locating it, referring to the owner's manual can provide specific guidance for your model.
Use a heavier weight
Check your fuse, ign switch and kill switch.
open the helmet lock on the left side of the bike, then pull the lever located behind the helmet lock toward the front of the bike. this should release the seat.
There are two star-head screws on the rear of the ignition switch.(Actually reversed star-head screws) You need to buy a special tool to get them off.
you can easily get the service manual online for free (same as the kz750), highly sugggested. cylinder head nuts figures are first 2.5kg.m or 18ft lbs in a criss cross pattern then to 4.0kg.m or 29ftlbs. the bolts are 3.0 kg.m or 22ft.lbs. valve cover figures are 104inlbs or 1.2kg.m. once put back together warm up bike thoroughly then retighten to specs. just changed all gaskets that, was a pretty easy job. good luck
If the oil pressure light is flickering on your GPZ 500S, it may indicate low oil pressure, which could be caused by low oil levels, a failing oil pump, or a clogged oil filter. Check the oil level first and top it up if necessary. If the oil level is adequate and the light continues to flicker, it’s advisable to have the bike inspected by a mechanic to avoid potential engine damage. Ignoring this warning could lead to serious engine issues.
I think this is a simple gravity feed to the carbs. It's possible you require some vacuum from the intact manifold to open the flow. Some Honda Nighthawks are set up that way. The stock from the factory 1982 GPZ 1100's (B2) were fuel injected with a pump located below the battery tray providing 33 PSI on turning the key to 35 PSI while running. A suitable replacement is a MSD # 2225 fuel pump using a new fuel pressure regulator from www.mpsracing.com/NOS/no01z.asp
The gpz1100 a1, it was even advertised as the world fastest production motorcycle at the time. i know I bought one. it was superceded by the gpz 900, an iconic motorcycle which took some of ithe 1100's design cues with a better engine and became the first modern sports bike.