Oil does not show in oil level window

Depends on the capacity, the oil should be visible at the window, if the bike is leveled and you still do not see the oil at the level you are simple to low on oil.

Do it when its cold you are Right .

Have a friend hold the bike upright. Then look through the oil level inspection window (with the motor off) and make sure the oil level is either between the high and low mark or up to the high mark.

Make sure your oil level is where it should be-if it is, get it changed, and get a heavier viscosity oil installed, i.e., if you are using 5W-30, go to 5W-40-also pay attention to your idle, if it is low, it will cause the issue you are experiencing-your throttle position sensor, Idle air controller or (worst case) your oil pump may be causing this (also the oil pressure sensor)-easiest thing to do is get the oil changed, you do not offer information that would make answering this, like YEAR, ENGINE, MILES, how long since last oil change.

Some of the motors have the sight glass on the side of the engine with level indicators - look next to where your right foot would go - there should be a window about the size of a quarter. Make sure the bike is level and fill the oil til the oil is at the full level on the sight glass. Always screw in the dipstick if the level on that is to be trusted.

Loss of oil pressure is rare unless there's also a leak or not enough oil was added when changed. Check the oil level with the dipstick. if it dosen't show a level between the marks then look for a leak, [ the oil filter may not be seated properly, lines to the cooler, drain plug, etc. ]. If no leak is found, then not enough oil [ or none ] was put back in when changed. If it has no oil then don't add any or do anything to it, chances are the motor is ruined.
If this was done at a shop, then you should contact them first, if you get a run arround then contact your state's comsumer protection agency.

Your bike does not have a dipstick it has an oil check window on the right side of the motor. Have a friend hold the bike upright on level ground . There should be a dot at the correct oil level ,or a high/low mark bar in the window to tell you where the correct oil level is.

it sounds like there is to much oil in the engine the same thing happened to my zx6r, hold the bike upright on level ground then check oil level on the glass viewing window which is on the right hand side of engine, you should see oil level between the low and high marks, if level is above top line you will need to drain some oil out by undoing sump bolt or using a siphon, when ever checking oil level bike needs to be upright on levelish ground some people check oil levels when bike is on side stand which is wrong as it shows oil level as low when in-fact its probably right

If you check here you will see that #18 is "gauge-level"
This should show you the oil level.
Remember: Put inside the 2/3 of the total amount of oil and run the engine for 5 minutes.Then kill it and add the rest of the oil to the proper level.

Start checking the oil level, if oil is low then the problem is a leak or weared rings.

If oil level is ok, check that the oil pump has enough pressure.

If oil pump is also fine, then scan the ECU (car computer) and replace the sensor if you do not find anything else being wrong.