Had trouble finding a sparkplug cap for my 86 zl-900. I put in a different cap, but it doesn't seal the sparkplug chamber and my bike has a hesitation when I hit the throttle? Also, how much oil do I need to put in when I change it and the filter?

I use 120cc each side of medium but I have found that a little hard except on warmest days but my forks have modified two-way dampling internals from CBR600. Standard is 169cc each side.

The firing order is 1-2-4-3. The left cylinder is #1.

1&4 fire on the same coil and 2&3 fire on the same coil.

What type of coolant do I use for my 86 eliminator?

Japanese bikes change things so often it gets near impossible to find direct replacments.
You may want to try klsupply.com (K&L Supply Co.). Back when I used them for older bikes they seemed to have a good selection of after market direct replacement parts.
You may also be able to look up OEM parts and numbers at Riva's web site (search "riva" or "riva motorcycle parts"). Its a dealer ship with a parts locater where you can view the microfishe and get part numbers.
Lastly you can also try Tucker Rocky. Its a wholesaler but that is one of the larger suppliers to the motorcycle parts stores.

Hi
Thats the float valve seals not shutting off, did you clean them & set the float heights?
The overflows from the carb bottoms must also be blocked for the fuel to fill up the carbs which then leaks into the air filter
Check also that the fuel tap turns off when bike is not running

Ride Safe
Bike-Doc

the clutch may be frozen in place. try disengaging the clutch, sit on the bike, and rock it back and forth and hard as possible. this may dislodge the clutch plates. it usually happens if the bike has sat for a while

It's surging because of irregular fuel supply. There are numerous circuits in a carb and x the no. of carbs. The first recommendation is to have the carbs aynchronized. Under heavy throttle a circuit other than cruising kicks in making up for the higher demand. You can sync them yourself with a manometer. They sell at the bike parts stores. Hook up four vacuum lines (supplied) and adjust the carbs to mach in all columns. good luck.

Ck the fuel tank petcock for proper position. Fuel is filling your cylinders and pasing the rings into the crankcase. Diluted oil will take out bearings. Good luck. I you must, turn off your fuel when parked and not running.

I don't believe so,different bends on exhaust to accomodate different frames

sounds like your cdi box is faulty