XR100R wont start

[ThePixel]

Well here we are again, Basically it's as simple as that. My dirtbike refuses to start. It's a tangled mess of issues, pretty sure the carb isn't tuned right nor idled right, so that could be an issue, my spark plug is most likely bad, I'm not sure if compression is bad or not, but goodness I need somewhere to start, I'm trying to diagnose everything step by step but it gets more confusing the more progress I make, help?
It turns over but won't "catch" if you get my meaning. Where to start with this..

 

[Rich Rohrich]

Start by determining what DOES work. Verify you have good spark, check the compression, and put fresh fuel in the bike. If it has good spark, good compression and fresh fuel it should have a reasonable chance to start. If it doesn't then looking at the carb would be a logical next step.

 

[ThePixel]

Start by determining what DOES work. Verify you have good spark, check the compression, and put fresh fuel in the bike. If it has good spark, good compression and fresh fuel it should have a reasonable chance to start. If it doesn't then looking at the carb would be a logical next step.

Okay, thank you sooo much, Now being new to emptying gas tanks (Cause mine is 1/3 full)would it be correct to simply empty it through the carb drain tube or.. is there a quicker way?

 

[Rich Rohrich]

Pull the rubber hose going to the carb from the tank and drain it there.

 

[ThePixel]

Okay Update,
THE BIKE STARTED AND IT RUNS!!
I tweaked some settings with the carb, I turned in the fuel mixture screw a tad, turned out the idle screw a tad, and It sputtered a little bit but I managed to get it warmed up and running, will see how it works tomorrow off a cold start, I was told by my friend that it needed a thorough carb clean, and some fuel mixture adjustment. The bike for the moment DOES NOT idle unless you give it gas, I've tried messing with the idle screw but decided not to tinker with it much more as I had a running bike. What do you think Rich?
EDIT: My friend also happens to be the previous owner of said bike, so he is.. considerably credible.

 

[Rich Rohrich]

If the bike has been sitting for any length of time cleaning the carb would make sense. The pilot jet influences the idle and it's a very small jet so having it get plugged or partially restricted is pretty common. When it's restricted it will be tough to make the bike idle properly. Once the pilot jet is clean a good starting point for the mixture screw is to turn it in till it lightly seats then back it out 1.5 full turns.

 

[ThePixel]

Okay, thanks, will try that.

 

[Rich Rohrich]

Sometimes it's just a matter of sorting out a few little things to get it going.