That piece of fuel line at the inlet of the throttle cable is nothing. If you want to replace it with the rubber boot that comes with a motor, go right ahead. It is not a source of an air leak. If your throttle cable is uncoiling or worn, replace it. But it too is not a source for an air leak or the cause of a bog, There should be some slack in the throttle cable.
You have a racing engine. It’s not going to idle. Never going to beat any one on the track by idling.
If you have an unsealed motor, no log book and know idea of how many hours its ran, send it to a shop for a full rebuild whether you’re just going to just practiceor race it. If it blows up, it’s going to be more expenssive than a rebuild. Keep track of run time when it gets back.
LAD Specialties customer / tony kart / rotax / kt100