i bought a 250cc redcat quad last week. it was missing carb so i bought a new one it has good spark, getting gas and good compression. but will not run... it will just crank... sometimes i will get a loud pop out of the exaust. whoever had it before me messed with the 2 adjusters on the head. i think they are for timing or valve gap? i have no idea how to check timing on it. does anyone have a picture of the 2 adjusters on a running bike? any help is wanted thanks

 

I don't have a 250cc quad. Have you tried searching youtube for videos on 250cc valve adjustment? It seems to me a remember seeing some a while back.

 

Just had a similiar issue on my recently bought tao250E, followed video advise on youtube and got atv running. Remove carberator, unscrew float bowl, renove the two jets and spray carb cleaner in both until you see cleaner shooting out jets. screw back in jets, install float bowl, re-instal carb and start.
I did get told from where I bought them to return carbs to them and they would bore the jet holes larger so more fuel is gotten and little bits of junk won't clog jet holes again or as easily any way. Should have carbs back by next weekend. Also seen where you can adjust the slide pin to allow more fuel flow also. Good luck.