Hi all 

The picture with my finger pointing towards the nut
What does this do, is it the clutch adjustment??
from the picture with my handle bar the cable is fully 
Adjusted out, and it gives a little bit point for the clutch
if I wind it in there nothing the clutch is fully loose.
The picture of the clutch, is a clutch from a 1976 dt
175 there no screw to put in the middle of the clutch
like it shows online.... please can someone explain
how I adjust the clutch.... cheers all 

Manual in Tech Library explains it. 

The 74-76 style on the 175 is my least favorite design.  Eccentric screw raises and lowers shaft/lever in engine.  Full range of adjust happens in one-half turn of screw.  wedge on shaft tightens internal pushrod clearance as lever is raised with screw.  That's best I can describe.

 

Im being stupid I know but do I turn the screw in or out? The screw on the nut in the picture??

Usually in to tighten and out to slacken. However, do it half a turn each way and you'll soon see to confirm.

Right il give it ago and see what happens 

It's not about "in" or "out" on this design. 

Loosen the locknut and turning the screw will RAISE AND LOWER the arm on top of the engine if the eccentric pin on end of screw is engaged in the groove properly. 

When arm is up as high as it will go, intermal clearance is at minimum.  When arm is as low as it will go, internal clearance is at maximum.  See "wedge" that contacts pushrod in picture I posted to understand.

Which way the screw gets turned means nothing as it depends if eccentric pin is to left or right of center when you start.  So if you want to reduce internal freeplay you turn screw whatever direction you need to to raise the lever up higher.   To increase clearance, you turn screw to drop lever down.  Remember that full range of adjustment occurs within only 1/2 turn of screw!  Turning the screw excessively in or out can disengage eccentric pin from groove (too far out) or jam the shaft and even break the little pin (too far in). 

Here's a picture of the eccentric (offset) pin on end of adjustment screw that raises and lowers the lever/shaft/wedge.

 

OK im going to read that a few times, ive already taken the screw fully out by mistake, what am I looking for should 
the clutch lever on handle bars be hard to pull hard?? There is adjuster on the cable i think im getting totally confused...
the adjustments screw is about in the middle not fully in
Or fully out. What ive done is loosen the nut and then turned
the screw then tighten the nut and saw if lever on handle bars felt harder to pull and im just gone round in circles adjusting 
cable adjusters, and turning the screw in and out...
what do I need to start from scratch?? And am I looking for the clutch lever to hard to pull? Its a brand new clutch, brand new friction plates... il re Read the previous comments again...

Yep, ya only get half a turn to raise or lower the arm. If ya torn in too far you'll lock it up then need to go back maybe a turn to then be able to go right & left that half turn. You'll see the arm move back & tighten cable or go the other way as tharm drops down. There's probably a mark on the case for the arm to come back to as the optimum point of lift but don't worry about that if ya not perfect or have to come back further to take up cable slack--within reason that is.

Going to gently and slowly turn the screw and see which 
way it needs it