New here and need help!

[89blaster89]

I got a 93 kx 80 today, it starts up and idles great but i have a few questions. the bike is all stock but the air filter was destroyed! so i put in a twin air filter i had laying around, it fits ok but not the best. the pipe also has a dent right at the head of the pipe filling in about 1/2 of the pipe so im guessing its cutting off airflow. what main jet should i have in this thing? what should compression be at? and what is the little flappy thing in the exhaust port? i will also be mixing it 32:1

[USMC 500]

Welcome to the site.....you can find lots of info here and for your ride you can always look at the KX100/85/80/65/60 section for your machine.....In fact, don't be surprised if this thread gets moves to that section.

It sounds like you are gonna have to spend some money on this thing......The air filter for one should not "kinda" fit.....it has to fit perfect.  The threat of sucking particles into the engine is too great and it would be horrible to end up spending big $$$ over a $25 air filter....

The pipe must be replaced.....2 stroke performance suffers big time with the slightest dent in the pipe and if you say that it is half crushed at the head not only will performance suffer but there is also the likley chance that you will also harm the engine......Pipes brand new are about $200 but I've seen good used stock pipes online for $40 and up......

Main jet will depend on the exhaust that you end up purchasing, the elevation you plan to ride at and the temperature of the area you plan to ride in.....give more info and we can better assist you there.......

I'm not sure what the compression for you bike should be without a manual but I would think that for a small engine you should have no less than 120 psi of compression.....I'm sure that others here on the site can better answer this one.......

The little flappy thing in the exhaust port is called a powervalve........that flap will adjust according to the engine rpm to give you a broader power spread......make sure it functions properly especially on a little 80cc......

32:1 should work for you......you will get lots of opinions concerning what ratio to mix at but that is the ratio that Team Green used to recommend for their 2 strokes........

[89blaster89]

i dont have much money at all, i only plan to fix this thing up and get it rideing and running nice and then sell it for a 250.
anyway i could pop the dent out, i cant freeze it my dad would kill me if he saw a pipe in the freezer. i heard of a dry ice method though?
i will be buying a brand new filter soon. i also need to buy chain and sprockets and a clutch cable and lever