hi all new to trials and also two stroke engines but me and my two boys have all got beta technos each my youngest has a 1999 200 cc the other day when we went to start it after endless kicks it refused to fire .I removed the plug which was wet with fuel and a lovley blue spark re fited the plug and tryed again and it started but pumped out black oily liquid from the exhaust .after striping and emptying the fuely black liquid out of the pipe and giving the whole system a de coke put it all back together and gues what it wont start any one got any ideas please there's a 15year old with a upside down smile .