Good afternoon everyone!

    I just turned 16 last week, & my folks got me a 1972 Enduro 100 for my birthday! Not only is this my first motorcycle, its also my first motor vehicle of any kind! However, there's but one problem: The blasted thing's not working currently. According to my mom it ran like a dream when she bought it, but now it won't start up. I got to ride it for a good 2 minutes about. It took plenty of effort to get it to start, at least 100 kicks on the kick-start. When it did run, it felt severely underpowered. It could barely make it up a slight hill, & it was a chore getting it up there at all. Now, about a week later, I tried starting it again, but now it's gotten even worse. Now, I couldn't even get it to run for 1 second. The kick-start feels really stiff, it only goes down with the mightiest of a stomp. Not to mention, now it's leaking gas. We suspect either the spark plugs are bad or the carburetor needs cleaned. I figured if anyone would know what's gone haywire, it would be all of you. Based on my description, what do you guys think is wrong with it? How should I go about fixing it? Any & all help is appreciated, thanks!

                -Gunier J. Kintgen, Your Pal.

Look to the cylinder...

Could you please elaborate?

Realy difficult to take a guess but if your mum said it was running good then how long has it sat since last run.
It's possible the motor has flooded with fuel if the fuel tap has been left on & if there's a fault in the carburettor fload shut off valve.
If the crankcase got a lot oif fuel in there then a big 'stomp' on the kickstart could push the crank seal out from one side & often the worst side to fix 'which is the right side'.
Sounds from what you're saying that it might be hydraulicking when kicking over if its got lots of fuel in the crankcase.
All a wild guess & exhaust could be blocked up too in the tail section.
Best idea is post a video via youtube etc & lets hear what its doing.
I'm guessing it's an LT2 100?. Pics can be posted via "imgur" or similar.
We love pics & videos to 'help us help you'.
Welcome too from NZ downunder.
ps, i checked out your animation channel also. You've been busy, great work.

I had an LT2 as my first bike.  It flooded with gas often!  You MUST turn off the petcock on the gas tank when you park it!  The spark plug is probably wet with fuel. 

And make sure the "autolube" is working or that you're adding the proper amount of two stroke oil to the gasoline! 

If you have the stock chrome air filter with the "fuzzy foam" element, get a new air filter element from Yamaha, oil it properly, and install.  It can look clean and in good condition but mine was only a couple of years old and was the reason for no power.  It drove me crazy for weeks trying to figure it out. 
 

Ah, so this is a common problem on LT2's, all the gas leaking out of the tank? 
What the heck is "Autolube"? What does it do?
What mixture would you recommend, how much oil should I put in the fuel?
Where is the "Fuzzy Air Filter" located, & how do I know if I have one? How hard is it to replace if I do have a fuzzy one?
Thanks again!

Scroll way down this page on the right until you find LT2 which covers that bike only with the correct pic for airfilter etc.
4--19 or page 48 but the numbers didn't show as they should although i might've been too impatient as it was loading.
The complete manual to look at.
Says 1972 LT2 service manual under the pic.

www.legends-yamaha-enduros.com/yamaha-enduro

blimey, they're everywhere now i look. spoilt for choice.
plus the Other one in previous post i think,.getting confusing haha.

www.legends-yamaha-enduros.com/_files/ug...a652d.pdf?index=true
www.legends-yamaha-enduros.com/_files/ug...64fc2.pdf?index=true
www.legends-yamaha-enduros.com/_files/ug...84785.pdf?index=true
LT2M is the Go Fast model so not entirely relevant.

I do wonder RT325 about whom yer txt’g too

Sneezles, not sure what you mean?, are the links not showing. What have i done haha.