Bought this 2002 KLX 300 bike a few weeks ago and it wasn't kicking over so my buddy and I pulled out the carb and roughly cleaned it out. Popped it back in and got it to start but it's not sounding good when it idles at all. This is my first bike so I'm learning as I go. It sounds like it revs up real quick and then falls back off just as quick. Then cycles like that. Any suggestions to get sounding smoother? We played a little with the fuel mixture pin and the idle screw but that didn't seem to help too much. I can upload a clip if necessary.

 

Upload a clip.

 

 

Was the bike warmed up with choke off in that video?
Looks like you may still have a little fouling in the carb. The pilot jet is very tiny and difficult to clean. Other circuits may have some fouling. I think you may need to take another run at the carb with a careful, thorough cleaning. Then check for vacuum leaks when you put it back together. Check to see that throttle cables aren't hanging up.

 

The choke was on in this, engine was still pretty cold. I'll take another go at the carb. What's the best way to clean out the pilot jet? I have an air compressor and some carb cleaner I picked up at autozone. Best way to check for vacuum leaks? Thanks btw.

 

Do some google and youtube searching around.
You can try to find tiny wire to clean the jet, or just replace it as it is pretty inexpensive. I have a set of jet cleaners. Vacuum leaks can be located with WD40 and/or unlit propane sprayed around the carb boots and intake. The sprayed fluid/gas will make idle increase or decrease if there is a leak.

 

See the marks are horizontal with the head.
If you didnt find any air leaks, or dirt in the pilot circuit, check your timing marks are inline and also the valve clearances.
to check them its fairly simple remove the top engine cover, go to the left engine side and remove the 2 circle screwable covers (watch for some oil leakage) then with a 14mm socket and ratchet turn the engine and align the "t" mark with the indent on the engine cover, now check the top rughr hand side camshaft gears there should be 2 horizontal marks inline with eachother. Also check the valve clearances with a feeler gauge.