Could anyone confirm if the ball bearing has to be in the push rod assembly for a 1G1 1976 DT175, since when you look at the parts for a DT175C its not shown and i'm wondering if my bike has a C clutch assembly, since with the ball in I have no drive at all? Before i strip it down again and remove the ball can anybody say whether removal of the ball will fix the problem?

Not sure what parts list you're looking at but a DT175C has the ball.

Impossible to say what your problem is. First question is whether it had the ball or if you just added one? And if you did add one, why?

The push rod under the pressure plate should be able to be adjusted to where the underside of the nail head is pretty much flush to the end of the shaft it's in...

I vaguely remember Yamaha tried to round the end of the pushrods and eliminate the ball on some models... didn't work so well... so then they had a bulletin with new parts that had a shorter pushrod and used the ball again.

In any case, it's not hard to tell if it needs the ball... without one when needed moving the lever on the case will maybe just barely move the pushrod at the extreme end of lever travel...

With a ball when not needed... or an extra one... the pushrod will move with the slightest movement of the lever and won't be nearly flush to end of shaft when all the way in. And the pressure plate won't compress the plate stack. You'll be able to jiggle the plates.

Mark,
Thank you for such a helpful response!!
The push rod is not flush with the end of the shaft when the ball is installed, so that would account for why my clutch plates still turn and as you say jiggle about! As soon as i can get back to working on the bike i will remove the ball and let you know if that fixed it.
Your earlier question about had i added the ball and why came about because when i bought the bike the previous unfortunate owner had bought the bike in a supposed running condition, only to find the clutch not working, therefore sold the bike on since he had no mechanical knowledge! I took the bike apart and in a box of bits found said ball and put two and two together assuming the ball had been missed during an earlier rebuild and as shown in some parts drawings. This could be why i have the problem and if your advice works i will post the results.

Mark,
Forgot to mention i was looking at page 37 of the Yamaha manual for 74-76 DT175C which shows exploded clutch details and NO ball is shown, but in the parts catalogue under B4 it is shown as item 24?????

It may be the 74 where they tried it without the ball and then went back to using one? In the "combined" manuals they often just pick one diagram and it doesn't always match all the models. Carbs especially.

Or I could just be imagining things about the ball not used on some models.

It's also not uncommon for the parts diagrams to be incorrect.

Mark,
I think you could be right, sometimes parts diagrams are just wrong!!!!!!!!!!!!

Hey Stu,

Glad you found your way here! (We initially got chatting via eBay.) The main problem I think is the clutch not engaging. The clutch rod / ball bearing thing may be one reason it's stuck open. The only other things I can think of is something jamming the plates apart (worn clutch basket but it'd have to be obviously terrible) or weak / wrongly installed springs. Again, bit too obvious

Way, way out there is some mix up in parts. On my DT I found the tacho cable was spinning the wrong way. Turned out someone had put the wrong gears in the case: both the worm gear and plastic cog (I'm guessing but probably from a DT125.)

tl;dr never assume you've got all the right parts when you get hold of someone else's project!

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Regarding the parts diagram I went with the "76 DT175 Parts" pdf and it's a close match bar a few things: loom, lighting and some of the electrics, mudguards/fenders, suspension and silencer. Engine is 100% the same AFAIK.

Thank you all i have now stripped down the clutch and removed the ball bearing which has given me a working clutch and gears.
My next problem is now i have two clutch cables niether of which work without placing an extra spacer at the engine end to shorten the outer sheath!! Do i need a particular cable to suit this unusualclutch without ball bearing or have i something missing??
Pictures attached show the problem.

My brain's starting to hurt thinking about this, but if you put a spacer in, then are you not effectively lengthening the outer sheath?

If the sheath really does need shortening, then you could either do it yourself or take it to an old fashioned bike shop to do (pedal or motor) - that's what I did with an aftermarket throttle cable for my RT2.

Uncle Al, Thanks as ever for sensable input, i have ordered the correct age cable and i will see what happens, but if as you say it needs shortening/lengthening i will have a go since i can solder and fettle so should be able to do!!