Does MOT allow the stainless hose clamp that has a screw that tightens the clamp?

yes my measurement was at the carb T...and my digital caliper is MIA so I had to use a plastic one, but it was my best guess

Whoops, just noticed You said 'Tee" so i guess you're referring to the carb tee? I just read your initial post and it didn't mention that but..regardless, it'll work on that too.

You have the smaller size, 5.5 X 6.4ishmm. A couple companies dominated the Petcock market back then, Mikuni or Taiyo Giken as supplied thru various brands. I'm betting you have the TG product. Ed is Correct for the Suzuki Hose but it only fits the Larger 7mm style barbs. If you're not concerned with a splash of color, use 1/4' Tygon fuel line. Readily available at "most" hardware/lawn mower shops. Like the hose Ed mentioned and original, it's thin-walled so assembly won't be a fight. It also is a friction fit but would suggest some sort of clamp. Tygon shrinks as it ages, contrary to what most person's don't care to admit. A couple of pictures to help you distinguish the difference, Have Fun!     

The lip of the intake T is 7mm but the stem is 6

H1Vindicator wrote:

how tight does the suzuki fuel line fit the fuel tee? 7mm is between 1/4" and 5/16". I'm using 1/4 on the vac line and 5/16 for the fuel. both seem to be a good fit.

Tight enough that it's easy to install, but won't pull off.  Repeating myself, no clamp needed.  I use a screwdriver to push off the hose when trying to remove the hose from the petcock, for example.  

Thanks for the comments.

So as I was concerned, I checked the bike yesterday and sure enough the fittings are soft "enough" to be serviceable for now. I'll keep an eye out for something that will work for the 305. I did cross reference the part # and seems it doesn't equate to any other bikes or part # on a first glance, but will continue my research.

Regarding the air ducts / radiator hosing donuts, I did get that to partially work on the 650 several years ago. Martin_CSR was the one in fact that had put together the suggestion for me iirc. The airbox mod I made was still the best method IMO with a permanent seal, and I personally never got the donuts to work quite right.

Thanks for the answers folks. I'll check these and give them a try / get off my lazy butt and measure the OD of the fittings. Might put together a table of the things that work for me so there's a single go to resource.