I have the same issue. My mechanic told me to change the CNG kit and installed a loderenzo in it. I have the same issue. In full tank, I get only 70-80km. I change spark plugs after a week or two because it gets engine oil and gets dysfunctional and the car starts missing. Also, starting is on 3-4 attempts. I'm going for a Ring piece in October. Any suggestion would be appreciated