Hi all just started another yamaha project a 79 french blue DT175mx with 9000 on the clock and dry stored for 20 years.I have installed a new standard piston and rings as bore clearance measured ok ,new gudgeon pin and small end.

I then started it up and am getting noise from the clutch and most of it goes away when clutch lever is pulled .is it the plates or the basket thrust bearing or something else any dt wizards out there please.

Hi

Not suggesting this is the problem your bike has, following a rebuild on my twinshock DT, (mains, big end piston etc). my bike rattled when the bike was ticking over in neutral, It was such a slight noise that I put it down the new parts just bedding in, unfortunately the problem was in the main bearing, the ball bearing retention / separator ring had split and a part of it was making a noise as the bearing turned, eventually the piece of this 'separator ring' broke off and found its way up the side of the bore and then into the exhaust port, obviously damaging both piston and bore, so if I heard the same noise again I would probably investigate this further,

Hope this is not your problem, as my bikes fault was in the worst case scenario,

Thanks for that and it could be a possibility but it seems to be less noise when the clutch is applied.

My DT doing the same after complete engine overhaul. Pull clutch lever in and noise disappears. Its done about 500km like that now.

Whip the cover off and have a look , there are small cutaways in the clutch plain plates to reduce clutch noise . They may be mis-aligned , if not, check the basket and centre for notching . If the original cluthplates are in the bike they may have stuck together over time . They're easily replaced .