I have a black and white 1976 DT400 UK bike which was restored before I purchased it. To my eye the bike is excellent and runs well now after fiddling with the carb although it prefers to go at full throttle everywhere !!
I believe at the moment I am not able to add a photo but I am trying to confirm whether the correct fuel tap is fitted. Mine has what looks like a very small makers mark with  T K stamped inside a circle. Also stamped on the carb is 4G. The tap weeps fuel from around the lever when turned on so would like a complete set of new seals. The seal behind the lever has three holes PLUS one very small hole which I think just locates onto a small raised point. The bowl underneath has a small cylindrical filter inside and the ring which fixes the bowl on is NOT the type for a spanner but for grips or even just to do up by hand. I can see many new or secondhand taps for DT400's but none like mine. I will attach a photo as soon as that is possible. Does any member know if my tap is correct and if so where I can get the "best" new seal kit from. ThanksI have a black and white 1976 DT400 UK bike which was restored before I purchased it. To my eye the bike is excellent and runs well now after fiddling with the carb although it prefers to go at full throttle everywhere !!
I believe at the moment I am not able to add a photo but I am trying to confirm whether the correct fuel tap is fitted. Mine has what looks like a very small makers mark with  T K stamped inside a circle. Also stamped on the carb is 4G. The tap weeps fuel from around the lever when turned on so would like a complete set of new seals. The seal behind the lever has three holes PLUS one very small hole which I think just locates onto a small raised point. The bowl underneath has a small cylindrical filter inside and the ring which fixes the bowl on is NOT the type for a spanner but for grips or even just to do up by hand. I can see many new or secondhand taps for DT400's but none like mine. I will attach a photo as soon as that is possible. Does any member know if my tap is correct and if so where I can get the "best" new seal kit from. Thanks   

Photos need to be uploaded via a third party host - I use Imgur.

TK did make petrol taps for Yamaha.

There were various versions of the fuel taps for these bikes, so photos would be very useful. By the way, the seals, when you identify the tap, are probably still available from Yamaha.

Thanks Gr8uncleal for the very quick response. I'm not good with computers but I'll get a mate who is, to help up loading a couple of photos asap.