Hi Guys is there a secret tool for using on the exhaust flange nuts for the DT 175 . a socket is to big and a spanner wont go on the 14 mm nuts . also are the side panels a matt black on this model ?. thanks as always. regards. Jez....

DT175s have 10mm exhaust nuts. Threads have probably stripped at some stage. Will be very difficult to take on and off with 14mm nuts. To avoid changing the studs, you will probably be able to get K nuts which are smaller spanner size?

As they went on ok, then it must be possible to remove them.

I wonder if a 14mm socket with a 1/4 in drive would do the trick - ie socket might be a little narrower.

A 10mm socket, only just fits, so not sure if you will have much luck with a 14mm? Why not try an open end spanner, with the end bent round so it goes on the nut?

Sounds a bit like the studs have been replaced with 8mm studs to be using 14mm socket size.
If thats the case, nuts for 8mm studs come in 14-13 & 12 socket size.
So go to 12 socket size 8mm nut.
If on the other if hand someone has fitted those crazy original yamaha 6mm/8mm step studs with the 6mm end into the cylinder then be very careful overtightening the nuts on the 8mm end sticking out as it'll break off for sure if overtightened.

The part number on Partzilla relates to that reverse stepped 6--8 stud. Here's a link.
#https://www.nospartsnow.com/nos-yamaha-dt125-dt175-dt250-dt360-dt400-ty250-exhaust-stud-bolt-90116-06146/
That's for a "74 DT175A which looking back through your posts it looks like what you must have.
So go get some 12mm socket size 8mm nuts.

photos.app.goo.gl/7Gv6Vim6qyrZaAW58

Chances are the genuine nut is 12mm socket size & thinking of clearance to the pipe.
www.partzilla.com/product/yamaha/95333-0...9bfb6e3f7acbdafb5034

Hi Fellas , so the studs are 8mm and i managed to get some 13mm stainless nuts . with a little bit of fettlin we got there. thanks for the help . best regards. 

12 is quite common with or without a flange if you want an easier fit next time.
Good you got it done though.
These ones look a bit expensive now i look lol.
racetechtitanium.com/product/titanium-m8x1-25-flange-nut-2/
I see they're titanium now i look again, No wonder they're expensive.
Be ordinary cheapies out there i'm sure.