ok it's not quiet a kombi but it's on a 1600 tp The brosol 30/31 has two jets on the side of the carby power and idle jets. But these don't seem to seal well. I can blow air in through a drilling and bubbles come out through from around the thread. Looking at the construction of the jet it's self it appears to have two sealing surfaces - 1 on the face around the jet it's self and the second is a shoulder just before the start of the thread. The problem is the carby it's self has now shoulder for the second surface to mate against which means the thread is the only place it can seal and it's a rather loose thread so no chance of the thread sealing. I've read lots about the erratic opperation of the Brosol carbies and wondering if this sealing (lack thereof ) is the cause of the problem. To rectify it I am considering using Teflon thread tape on the threads to get them to seal up. I'm certainly no carby guru so maybe I'm barking up the wrong tree. Any comments or suggestions would be warmly received. Also some technical documentation on these carbies would be great if some one has some they could share.