I have no idea what 1/2a tubing looks like but if its the cause of your drama then its not nonsense and hardly the fault of the engine . Everyone's done something dumb in this hobby so as long as we learn from it !!!! . You could have a thread 000;s of pages long on that subject . Its the dudes that do it every week that makes you chuckle .It would be a shame to be turned off of 4 strokes as there pretty cool . Cheers the pope