1972 WR250 the beginning

And what about this! I found this photo of a clutch that I adjusted to even the gap between the pressure plate and the disc stack. Had to tighten the nuts more than 9 turns. I used feeler gauges to make sure the gap was even since we're dealing with a gap of only a couple millimeters. Notice the difference in the amount the nuts are screwed on to the studs. The spacer mod would not have worked with this disc stack as the gap .



This is a new build and the nuts are not the same height indicating the need to adjust the pressure plate to clutch stack gap.

I was also talking about the clutch unload distance. .not the smoothness if operation. As you stated the originals are probably not the same as a new set by a mile. Your test on a slope is good but could change with the weather temps. There is no absolute in dirtbike clutches. Thats why the cables have adjusters.

Interesting observations Crash! What might your thoughts be as to why the 75 and on clutches with the distance sleeve (spacer) work as they have similar components as the earlier 'big clutch' engines? Is it all due to spring 'strength'?

Also, took a quick measurement of the clutch studs and only two of the eight were of similar length - the others varied.

Great question. My guess is that spring manufacturing improved by 75 causing the springs rate to be similar in a particular mfg run thus eliminating the extreme deviation found between springs in earlier years. Other than that I got nothin'.

Interesting but I suppose we shouldn't be surprised considering mfg tech in the sixties and seventies was not what it is today, especially on a dirt bike. Maybe HVA decided that a solution to the springs deviation would be to implemented a shop manual instruction to check the pressure plate to clutch stack gap during assembly instead of adding more parts to the product, i.e. sleeves.

IDK, your guess is as good as mine but, I do know from experience working on multiple pre 75 clutches that the gap between the pressure plate and clutch stack varies when the all the spring nuts are tightened the exact same amount of turns, like what would be found when spacers are used. How much the gap would deviate around the clutch when spacers are used would probably vary from clutch to clutch allowing the them to work in some cases. Bottom line, check the gap upon assembly with or without spacers.

Now you're just trying to confuse me. HaHa. Seriously, your right. The adjusters are there to fine tune the pull distance as things wear.

Merry Christmas Friends!!

You too Chris! Thanks to both yourself & Crash for keeping this site fun! Hopefully, we get some of the old timers back & posting : )

And to you as well! A Prosperous New Year to all!

Just an observation, (I never worked on one of these clutches) but if the studs where all not the same height, then it seems to me that some of the nuts would be wound on tighter than others to achieve the correct (and even) gap of the clutch stack. By adding spacers to those studs that would make the clutch stack the same height on all eight of those studs, correct? Just trying to learn, that's all. I have a 77WR250 and my clutch is a little different.

Thank you, John

Hey John, the spacers wouldn't support the clutch stack, they indirectly support the pressure plate via the 8 springs. Keep in mind, an uneven pressure plate would occur only when the clutch is disengaged and the pressure plate is being supported by the 8 springs.

Check out the work shop manual photo in post #64. The potential for an uneven pressure plate is why the factory recommends checking the pressure plate lift. Its also been recommended to me by LaFevre at Vintage Husky.

Why your 77 clutch design doesn't require checking the lift is something we've also been discussing.

Hopes this helps ya out.