199A Clutch Drag

[scot taco]

I,m not sure if it,s the correct terminology,but the clutch drags on my 199A.When riding the bike and you pull in the clutch it doesn,t fully disangage and the bike tries to keep going with the pressure plate correctly adjusted and slight free play at the lever.

Before pulling it apart I did check the pressure plate trueness by pulling the sparkplug,then kicking it over while holding the clutch lever in- it was pretty much spot on.So I pulled it apart and the basket has no wear grooves to speak of.I,ve never seen that before and it doesn,t look like they,ve been filed smooth.Anyway,I don,t think the plates were hanging up on the basket.The hub looks ok with very slight wear marks and a few nicks on the ends that look to be made from a tool in clumsy hands.

I have not cleaned and inspected the plates yet,but they are the stock steel ones.I,m just looking for any suggestions on how to cure it and what else to look at or do that I,ve missed.

[nigel dabster]

Correctly adjusted is what?

I set mine up to "just slip" in 6th on the road/freeway.

Do the plates pull off square?

[scot taco]

By correctly adjusted I mean that I first set the pressure plate free play by running the adjustment bolt in until it makes contact with the pushrod then back it off a quarter turn then tighten the lock nut.I then adjust free play at the hand lever to about an eighth inch.

The plates did push out squarely,but didn,t seem to push out real far,but maybe it shouldn,t? When I had the sparkplug out and pulled in the clutch lever to kick it through and check for trueness/spring adjustment it would drag and turn the clutch basket every second revolution or so.

When it goes back together and I put the springs back in I usually run the nuts down so they are flush with the end of the stud.I then kick it over and adjust the spring tension accordingly so that it pushes out sqarely.Does that sound right or am I doing that part wrong?Any tricks of the trade or advice on what I may be doing wrong are appreciated.

Thanks for the reply Nigel

[pigbog]

I would check the operating lever/push rod mechanism - if I remember rightly there's a ball bearing at the end of the push rod. It could be that something's not right and you aren't getting enough movement to separate the plates?

[woody]

On thing to check is that the pins that the nuts screw onto aren't bent slightly. They're pretty weak and bend easily. If just one is off centre, the cup that the spring sits in can foul on the pin and stop the pressure plate coming off 'square' on that pin, the result being, the plate doesn't come off as squarely as you think it is. Take all the springs and cups out and eye up the pins in the holes of the pressure plate. They should be dead centre. If not, they're easily bent into the correct position with a screwdriver.

From what you've said, your adjustment of the freeplay on the pushrod has been done correctly, so that brings you back to spring tension. Once you're satisfied the pins are true, reset the tension. They don't all necessarily need the same tension to get the pressure plate to come off square. I've had them where one is a full turn more / less that the one next to it.

Is the clutch arm positioned correctly on the timing cover. If the angle is too far forward you may not be getting full travel on the rod.

Correct number of plates fitted?

[feetupfun]

The pressure plate travel is not much on a Bultaco clutch, so the flatness of the plates is very important for having it release fully.

[pschrauber]

Look up if you have the push mechanism of he clutch lever right adjusted.

May be you have too much "free space" / play between the push rod and the clutch level shaft. You can adjust the space on the clutch side when you remove the plastic tap that sit's in the clutch case just in the center of the clutch. There is a adjusting bolt and locknut situated. The play should be around 2 - 3mm, not less! but not more.

Another commen problem is a push rod which was adjusted with too little play, then the ends of the rod should have got marks as they get in touch between each other without the clutch is engaged. There can be friction marks at the end of the clutch push rod, the push plate and even in the balls itself. Then you have to replace them.

BTW:

Please leave the spring on the shaft lever, as this spring is responsible for leaving the clutch shaft in the initial position and then you won't have friction between the push components of the clutch. Some people believe it's a nice trick to make the clutch action lighter when you take this spring away. And it's true without this spring the clutch action is a little bit lighter, but sadly without spring you will wear out the clutch push mechanism very quick, therefore - in my opinion - this tweak is nuts.

[scot taco]

OK,I had a little time to get out in the garage to clean and inspect everything.I think I might have a few problems.

One is possibly the bent studs in the clutch hub.It looks to me that three of them are off.Thank you Woody,that is something that I did not know or think of to check.

Also I found two of the clutch plates are warped,although I,m not sure of the best qay to check.I started by laying them on a piece of picture frame glass and then held the ones that were warped against a flat one to compare.Thanks Feetupfun.

I also pulled out the pushrod assembly to check it out as pigbog and pschauber suggested and it seems ok.The ends of the two rods that meet the ballbearing are in nice shape.The ball is 5.5mm.The pushrod is 187.3mm in length and the whole lot - push rod,ball and end rod are231.7mm in length.Thanks guys.

I,ve added a few pics of everything just for grins.I think I need to polish the hub and basket and either replace the warped plates (I might have some old ones somwhere) or get a new set? Then straighten the studs.

[feetupfun]

As well as fixing the hub and basket, I would be fitting a set of Barnett plates. They are flat and because they use friction material, you can run with less clutch spring preload without slipping. You would have noticed that even the flattest standard plates have high and low spots. If you compare the Bultaco plates with the steel plates in many other bike clutches, you will see that the Bultaco contact pattern is on the inferior end of the quality scale. I have seen standard Bultaco plates ground flat on a surface grinder, which improves the contact area, but reduces the thickness of each plate so makes them even more likely to put grooves in the basket fingers and the hub splines.

Edited December 28, 2013 by feetupfun

[nigel dabster]

Flat plates are an absolute must, and slacken off the springs as far as you can do make sure they pull out straight as stated above, try frontera plates you can get an extra one in = less spring tension required.

[pschrauber]

Interesting, there is every day something new to see,

I have seen some broken clutches but never so different bended studs?

https://picasaweb.google.com/110483524567493669643/KTM500MXGSVorher#5454487688195618242

[woody]

One thing to be careful of if backing off the spring tension is that the nuts will foul the inside of the clutch case and it's not pretty if you start the bike and that happens - trust me... They can't actually be backed off that far before they do foul as they are quite deep.

What I've done is machine them to half their depth which allows them to be backed off as far as you want without them catching the case. With Barnett plates fitted, they require less tension, so a light pull can be achieved on the lever without the clutch slipping. The only pain with the Bultaco is that adjustment can only be done with the cover off, so if you back them off too much and then find it slips, the cover has to come off again. I generally set mine by riding it around the garden with the cover off before fitting it all together.

[bondy]

hi woody sorry to butt in but am just in the the middel off doing my 199B and will be doing the clutch ive got the new friction plates how do i set the center grub screw? i was told bottom it then back it of quarter of a turn. if i rember i think the throw out ball as worn down so will replace it.

Edited December 28, 2013 by bondy

[scot taco]

Thanks again for all the input.I will report back when I put it back together.I did forget to mention that there are a total of 12 plates,is that correct?

I like the idea of riding it in the yard before putting the cover back on.I had the one on my Ossa off three times in a day trying to get it right.

I will probably get a set of Barnetts,but I will check my spares first because I do have a 175 Frontera motor thats waiting to be turned into a 250 for a slimline sherpa project.Maybe the plates in it are straight.

That is a nice KTM pschauber.It would be a nice ride to work,but I,m afraid I would get to many tickets!

[nigel dabster]

hi woody sorry to butt in but am just in the the middel off doing my 199B and will be doing the clutch ive got the new friction plates how do i set the center grub screw? i was told bottom it then back it of quarter of a turn. if i rember i think the throw out ball as worn down so will replace it.

pinch it soft then back off so the lever has free play, grease everything when assembling, 1/4 turn sounds about right.