Gpz1000rx number 1 cylinder fouling spark plug, causing miss fire and light blue smoke

Fouled plugs may be caused by oil leaking into the cylinder. Does it smoke when running (cold), are you using up the crank oil. Black smoke is excess gas comsumption, blue smoke is oil burning. If your plug is fouled with black carbon, you are most likely running to rich.

Pull the spark plug to see if it is oil fouled, preventing firing. If it is, you may have a mechanical problem in cylinder 5- do a compression test to check for low compression in that cylinder.

If plug is clean or only showing black sooty deposits from unburned gas, the problem could be either in the secondary ignition (plug, plug wire, coil), or an injection problem. Try a known good spark plug and spark plug wire, also a known good coil, if plug and wire wasn't it. If checking for spark, you need to see a blue snapping spark when cranking engine to verify good ignition. A weak or orange spark, or intermittent spark is an ignition problem.
To check injection circuit on number 5, you can purchase an inexpensive "noid light" at parts stores. It plugs into the injector connector, and if circuit is good the noid light will be blinking when cranking the engine over. It is rare for injectors to fail, but if circuit is good and no gas is getting into the cylinder, injector may be bad or plugged.
Good luck.

could be a fouled spark plug swap it with another cylinder and see if the misfire changes cylinders

The most common cause of blue exhaust smoke is oil leaking past engine seals and into the cylinders where it then mixes and burns with the fuel. Oil leaking into the cylinders can cause a rough idle, misfire and fouled spark plugs. So best bet is to have a local repair shop inspect for internal oil leakage.

The blue smoke is OIL, coming from bad seals in the valves. It drains into the cylinders overnight and when you start the car it burns the oil off. This is probably fouling your plugs and if backfiring will fould the carburator. The miss firing is due to the age and most likely the timing of your engine, along with fouled plugs and carb.

Blue Smoke: Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles.

How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

SOUND LIKE TOO MUCH OIL GETTING IN COMBUSTION CHAMBER. POSSIBLE CAUSES.TOO MUCH OIL IN CRANK CASE.STUCK CLOSED PVC VALVE.WORN VALVE GUIDES AND VALVE SEALS ALSO BAD OIL CONTROL RINGS.

Blue smoke is never a good thing....

Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles.
How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

your engine has worn valve guides, piston rings An engine that burns a lot of oil (more than a quart in 500 miles) is an engine that needs to be overhauled. Normal oil consumption should be a quart or less in 1500 miles. Most newer engines consume less than half a quart of oil between oil changes (every 3000 miles). So if your engine is burning oil, it's essentially worn out and needs to be repaired.
Because the cost of overhauling or replacing an engine often exceeds the value of an older car or truck, many people will just keep on driving a "mosquito fogger" in spite of the blue clouds of smoke it leaves behind. Never mind the pollution it causes, oil is cheaper than a new or rebuilt engine they reason. That philosophy may be okay if you live out in the sticks somewhere. But in urban areas that require periodic vehicle emissions testing, an engine that's burning oil usually won't pass the test because of excessive hydrocarbon (HC) emissions. You may get by on a waiver after you've spent some money (in vain) on a tune-up, but the fact remains you're still a polluter.
An engine that burns a lot of oil will also eventually foul the spark plugs. Thick, black oily deposits build up on the plugs until they cease to fire. Then the engine misfires and loses power. Cleaning or changing the plugs may temporarily solve the problem, but sooner or later they'll foul out again.
Forget about "miracle" oil additives or pills that claim to stop oil burning. They don't. Better to save your money and put it towards a valve job and new set of rings.

Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles. How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

Blue Smoke: Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles.
How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder. I that doesn't work then i would get with a mechanic and have it leak tested for possible piston ring replacement.