Yamaha workshop manuals say to replace the clutch basket cush-drive assembly if there is any play. I found about 2mm of play in this DT200R assembly (identical to SDR/DT125R/TZR125 except for number of gear teeth and likely very similar to all wet-clutch TZR250s), so thought I'd have nothing to lose by dismantling it to see what was inside.
(https://pure2strokespirit.net/forums/proxy.php?request=http%3A%2F%2Fi1277.photobucket.com%2Falbums%2Fy485%2FJamesP001%2FDSC05524A_zpsnik56gib.jpg&hash=87561e3f48ad44c4b77196e2b0943929dccd72b8) (http://s1277.photobucket.com/user/JamesP001/media/DSC05524A_zpsnik56gib.jpg.html)
The only assemblies I'd dismantled in the past (much older European bikes) had springs for the cush-drive, but this uses rubber buttons. The six large rubber buttons perform the main cushioning duty, while the three smaller ones fit into the holes on the spokes of the gear (to prevent rattling of the clamping plate, I presume).
One of the large rubber buttons is round, one is almost round and the remaining four each have a flat edge which matches the raised blocks on the aluminium basket portion when the parts are assembled. The round and almost-round buttons were found in different slots. I wondered whether all of the rubber buttons started off round, but those with a flat edge don't appear deformed - it seems to me they were made in that shape.
The red "gasket" thingy is 0.6mm thick, made from some tough material which reminds me of Elephantide - it seems tougher than usual gasket paper. It appears to have been chafed/torn/deformed by continual movement, probably caused by the play in the assembly.
Although absence of play in the clutch basket cush-drive would be desirable, I can't see how a small amount of play would be detrimental (now that I know how the internals are arranged). New assemblies are very expensive and are no longer available for many 1980s Yamahas. If one can obtain the rubber buttons, rivets and a gasket (Dan...?), the assembly should be easy and cheap-ish to recondition.
Anyone had any experience in rebuilding these and/or know the specifications for the parts needed, or where to get them?
Thanks & regards,
James
It's very common for the dampers to wear or break down and cause free play between the primary driven gear and basket. The allowable limit is zero.
Search Yambits for clutch rivet and clutch damper and you'll find both. It's an easy repair, but an extra set of hands helps when peening the rivets. I heat the rivet ends and then peen. When done grind the rivets back so you have the same protrusion as stock. The dampers are quite rigid so can be fussy to install. A drop of oil helps.
I've repaired several RZ350 baskets, but the principle is the same for yours as well.
Excellent - thanks for the advice!
The rubber dampers in this particular cush-drive (the one in the photos) don't look worn and are not damaged, but do allow about 2mm of play. I can accept that excessively worn or split/damaged dampers should be replaced, but I'd be happy enough to re-use these ones if replacements are not available.
I'll have a look at the Yambits web-site.
Thanks again & regards,
James
As I said, the allowable play is zero. If you have movement you need to replace the dampers even if no damage is obvious. Over time the dampers harden and will shrink as they do so. If you don't replace them the 2 mm of play you have now will quickly get worse. The free play limit of zero is there so you don't hammer the basket as you dump the clutch and then have to take up that free play before making solid contact. That contact will result in damage if you don't fix it.
Yes - I'll certainly replace the dampers if I can get new ones. Although I accept that mine have likely shrunk, they are still quite pliable and I have a hard time imagining that they would crack or disintegrate until they had been used for quite some time more. However, I'll defer to those who have had more experience with these things than I :) .
I've had a look at the Yambits dampers and they are all round ones - none of the flat-edged type as in my photos. Yambits list dampers only for RD, RZ and earlier models. Although these are all the same (Yambits No.CPA026), I so far have no idea whether these are correct for SDR/DTR/TZR etc. - I will ask the dimensions.
Regarding the basket cush-drive assembly in my photos; I will unlikely rebuild it, as the clutch basket slots are quite badly notched (although could still be filed or milled flat). I bought the DT200R bottom end to get some spares for my SDR. The DT clutch gear has a different number of teeth to the SDR gear, so it would be of little use unless I change both primary drive gears.
Do the RZ350 cush drives have the thin "paper gasket" like that shown in my photos? Were these damaged? Did you replace them? If so, are they obtainable, or did you make your own?
Regards,
James
James
I did a few on my old TZ's and a few LC's.
I used countersunk screws and threaded the back plates also fitting half nuts loctite in place with the threads peened with a centre punch.
This has worked well and is a common mod on the TZ350/250 baskets.
Fondseca sell rebuilt kits for the TZ clutch and the parts individually. Not sure they will fit your basket but the rivets might and its worth asking the question. I bought two sets off them last year but still haven't got around to doing the job but the parts look the job.
http://www.fondseca.com/index.php?main_page=advanced_search_result&search_in_description=1&zenid=5bd70f351acde28e50531e444952a97d&keyword=clutch+rivets&x=27&y=6
I've received a reply from Yambits. The round dampers on offer (CPA026) are 22mm OD and 8mm thick, while the rivets (YBK014) are 6mm diameter and 25mm long.
It appears that a set of dampers with 22mm OD will take up all free play in the assembly, although the ones I removed are about 10.5mm thick (could the thickness have increased as the diameter reduced? ?:-|).
The rivets I removed are actually 6.25mm diameter (they had to be pressed out after disassembling the cush-drive), but a length of 25mm seems about right.
In spite of the Yambits dampers possibly being about 2mm too thin, I think they'd be worth a try (in the absence of ones which are of "correct" thickness) - I could perhaps make up some spacers to remove any axial play.
Quote from: jools
...I used countersunk screws and threaded the back plates also fitting half nuts loctite in place with the threads peened with a centre punch.
This has worked well and is a common mod on the TZ350/250 baskets.
I was thinking along similar lines Jools - I'm glad to know that you have tried it successfully. In my case, the back plate is 3mm thick, but the holes are too large to be threaded M6. Of course, an option is to enlarge the holes and to machine shoulders on plain M6 nuts so that they drop into the back plate, giving as much thread as possible. The peened-over sections of the original rivets protruded about 2.5mm "above" the surface of the back plate, so I should be able to use M6 nuts about 5-6mm tall (with shoulder machined 3mm deep). I may even have the nuts welded in position. I'd probably fix the screws with Araldite or high-strength Loctite, so that all parts could be dismantled with minimum fuss later (if required). M6x25 coutersunk screws will be suitable, with any excess ground off as required.
Quote from: epa policeFondseca sell rebuilt kits for the TZ clutch and the parts individually.
Thanks for that Pat. Unfortunately the TZ cush-drive buffers seem to be rather too long to fit in the space occupied by the round or shaped ones in the DTR/SDR cush-drive assembly. The rivets may well work, but are five times the price of the Yambits ones :o (although it is a set of six, not four!). Apart from being countersunk, I don't think there is anything special about the DTR rivets - they are quite soft and were easily drilled. Besides, now that Jools has confirmed that the screw method works, I'd be inclined to go that way if I can make it structurally sound.
If anyone knows of any other likely sources of clutch basket cush-drive buffers (for any bikes) which may be good for my application, please let me know! If no better prospect arises, I'll buy a set of the Yambits buffers and see how they fit.
I'd also be glad to know if any other bikes use a "gasket" like the red one in my photos.
Thanks again to all who have replied so far!
Regards,
James
If anyone is interested I can have this in France ( or other type of head, material ... )
or this
Quote from: James P on January 19, 2016, 11:00:30 AM
Quote from: jools
...I used countersunk screws and threaded the back plates also fitting half nuts loctite in place with the threads peened with a centre punch.
This has worked well and is a common mod on the TZ350/250 baskets.
I was thinking along similar lines Jools - I'm glad to know that you have tried it successfully. In my case, the back plate is 3mm thick, but the holes are too large to be threaded M6. Of course, an option is to enlarge the holes and to machine shoulders on plain M6 nuts so that they drop into the back plate, giving as much thread as possible. The peened-over sections of the original rivets protruded about 2.5mm "above" the surface of the back plate, so I should be able to use M6 nuts about 5-6mm tall (with shoulder machined 3mm deep). I may even have the nuts welded in position. I'd probably fix the screws with Araldite or high-strength Loctite, so that all parts could be dismantled with minimum fuss later (if required). M6x25 coutersunk screws will be suitable, with any excess ground off as required.
Regards,
James
James
you could open everything out so they would accept M8 csk screws - probably a better bet for added strength. just a bit of extra work to open out the countersunk holes to suit..
What I have done in the past is screw everything together, mount the finished basket in the lathe and turn the nuts down to the required clearance then peen the thread/nut joint with a centre punch
I think I used Wiseco Clutch rubbers when I rebuilt my LC clutch. They may do different size ones. Yambits don't have a good reputation for quality....
Quote from: joolsyou could open everything out so they would accept M8 csk screws - probably a better bet for added strength. just a bit of extra work to open out the countersunk holes to suit..
What I have done in the past is screw everything together, mount the finished basket in the lathe and turn the nuts down to the required clearance then peen the thread/nut joint with a centre punch
Hmm...not a bad idea Jools - definitely an option.
Quote from: 4l04everI think I used Wiseco Clutch rubbers when I rebuilt my LC clutch. They may do different size ones. Yambits don't have a good reputation for quality....
Thanks - I'll have a look.
Regards,
James
Quote from: 4l04ever on January 20, 2016, 12:13:35 AM
I think I used Wiseco Clutch rubbers when I rebuilt my LC clutch. They may do different size ones. Yambits don't have a good reputation for quality....
+1 on that, They sent me some awful crap. >:(
Footpegs, reflectors, cables - all junk
My search for new replacement cushions/rubbers has so far been fruitless. I did see these (http://www.uppracing.com/item.php?pid=266&cid=71 (http://www.uppracing.com/item.php?pid=266&cid=71)), which state "Banshee. Blaster...".
The Banshee and Blaster cushions are different (Blaster is the type I want), but the advertiser hasn't replied to my enquiry for more info after ten days >:( .
It looks like I'll have to start talking to a urethane moulder...
When I get around to it, I'll dismantle one of my spare TZR 1KT clutch baskets to see what type of cush-drive it has.
Regards,
James
Quote from: James P on January 16, 2016, 02:05:21 AMYamaha workshop manuals say to replace the clutch basket cush-drive assembly if there is any play.
After further research, I have found the statement above to be only partially true. Certainly there is a picture with caption in the official Yamaha TZR 2MA workshop manual, setting down the requirements for circumferential play in the clutch basket cush-drive. However, there is no such picture or caption in the official Yamaha TZR 1KT workshop manual.
Just to make sure, I spent an hour or so :( translating the few short paragraphs of Japanese text adjacent to the pictures dealing with clutch basket examination. The text mainly describes wear or damage that may be encountered on the helical gear teeth and clutch plate thrust surfaces and how to deal with it - nothing about circumferential play in the cush-drive (unless I've missed something). I've also got official Yamaha workshop manuals (in Japanese) for the SDR and DT200R - any mention of circumferential play is also missing from them.
Perhaps play in the cush-drive is only a problem if you live in Europe ;D ;D ... ???. I did manage to find a spare 1KT clutch basket assembly but, for once, I'm disappointed to say that it is in excellent condition. There is absolutely zero circumferential play and only some very slight signs of use on the clutch plate thrust surfaces. For this reason, I am hesitant to dismantle it to see what is inside. If I come across one in worse condition, I will definitely pull it apart for inspection. However, that may not solve the mystery of whether play in cush-drives is allowable or not. If anyone has any additional info, please let us know!
Regards,
James
Hello James,
I have a Dt200R with the similar problem, play in the transmission.
I still did not open my engine cause Im looking for the possible spare parts and localizing the issue.
But it feels like a play in the basket clutch. It rattle also a bit on idle.
Did you find all necessary info and parts ?
European DT125R is basically the same bike as the 200cc model. A lot of parts are interchangeable.
Pitty that I cant open your photobucket with pictures ..
Regards
Alex
Yes Alex - apart from the number of teeth on the primary drive gear, the DT200R clutch basket cush-drive assembly is identical to the SDR.
I still haven't found a source of new rubber cushions, so I just took the best cushions from all of my spare clutch basket cush-drive assemblies. There is some play in the rebuilt assembly, but it isn't much (about 1.5mm maximum, from memory). I'd still be interested to find new rubber cushions if anyone comes across a possible source.
If the photos would be of any use to you, I could send them via e-mail - let me know.
Regards,
James
Hi James, thanx for the reply.
Can you post please the size of old removed rubbers / cushions?
The first logical though is to look at rd250 (lc/f1-2),
they are largely available,
How did you connect back primary drive with the basket, with rivets (if yes what size),or with screws?
Regards,
Alex
Would it make sense to inject the gap around the rubbers with a 2-part rubber or elastomer? Or even a hard compound. Perhaps this could be done through a small hole or gap without disassembly of the clutch basket. You would want a compound that sets up firm and is immune to oil.
Quote from: alex_d on September 24, 2017, 11:17:42 AM
Hi James, thanx for the reply.
Can you post please the size of old removed rubbers / cushions?
The first logical though is to look at rd250 (lc/f1-2),
they are largely available,
How did you connect back primary drive with the basket, with rivets (if yes what size),or with screws?
Regards,
Alex
There are six rubber cushions; two of them are completely round and four of them are almost-round with one flat edge (I can send you a picture via e-mail if you want). The round ones are about 22.5mm diameter and about 10.5mm thick (RD/RZ cushions are same diameter, but only about 8mm thick). You could probably use six round cushions if you wanted to, but I couldn't find any new ones of the correct size.
You can buy new rivets to reassemble the cush-drive (the rivets are the same as RD/RZ), but I reassembled mine using screws as follows:
a) Drilled three existing holes in clutch basket out to 1/4"
b) Using Recoil brand thread repair kit (similar to Helicoil), tapped the holes through and screwed in M6-2D inserts
c) Reassembled using M6x16 high-tensile button-head Allen-socket screws, secured with high-strength Loctite
Quote from: Hoatso on September 29, 2017, 03:58:33 PM
Would it make sense to inject the gap around the rubbers with a 2-part rubber or elastomer? Or even a hard compound. Perhaps this could be done through a small hole or gap without disassembly of the clutch basket. You would want a compound that sets up firm and is immune to oil.
I'm not an expert on the properties of such materials, but would expect that each cushion would have to be a homogeneous mass for it to work correctly and last for any appreciable length of time. I would imagine that any added material would simply get squeezed out fairly quickly. No doubt new cushions could be moulded/cast from suitable material though.
I did think of having new cushions machined from some material, but I doubted my ability to find such a material with suitable resilience/toughness/hardness/oil-resistance/heat-resistance...and whatever other properties the material must possess for such duty.
It would be nice to find a company which is experienced in making such items and can make new ones to a customer's dimensions - I have been unsuccessful so far :( .
I found a couple of (presumably small) firms in USA advertising replacement cushions for the YFS200 (same as SDR & DTR), but neither of them replied to my enquiries :( .
Of the larger firms which supply cushions for various models, Hinson was distinctly unhelpful and I didn't even bother with Wiseco (due to similar responses in the past when making technical enquiries). Neither of these two larger firms seems to offer any replacement cushion of the correct size (for the YFS/SDR/DTR) at present.
Regards,
James
Hello James,
thanx for this excellent info, please see as message my email for the pics of dampers.
Check this SDR clutch play video, did you had it same ? : https://www.youtube.com/watch?v=yTKmnAJt3Fw
He made also a custom USB programmable CDI for SDR.
He is doing some interesting research on SDR ( R-1z too).
Regards
Alex
Alex,
I've sent you some photos by e-mail. I have seen other videos from that source you mentioned, but not the one with the clutch baskets.
The amount of play in my various clutch baskets was less than the worse of the two in the video, but was still noticeable. I also had a little play in the small kickstarter gear on all baskets, but again it was much less than the worse of the two in the video.
Regards,
James
Quote from: Hoatso on September 29, 2017, 03:58:33 PM
Would it make sense to inject the gap around the rubbers with a 2-part rubber or elastomer? Or even a hard compound. Perhaps this could be done through a small hole or gap without disassembly of the clutch basket. You would want a compound that sets up firm and is immune to oil.
Firstly, according to Norbo's Forum some engines come with play even when brand new !
Secondly though I've never dealt with transmission play here I dealt successfully with loose cush rubbers in the rear wheel by applying it on the internal & external straights using Silcoset 151 ( you can get that in the UK from Cromwell Tools - there's now a 152 version available but I haven't used it yet ) - 151 is quite firm when it sets & I trimmed it as necessary with a blunt razor blade.
How it copes in oil I've no idea, but it seems likely it'll stick better to surfaces that are chemically clean?
Quote from: James P on October 06, 2017, 03:51:09 AM
<SNIPPED>
I found a couple of (presumably small) firms in USA advertising replacement cushions for the YFS200 (same as SDR & DTR), but neither of them replied to my enquiries :( .
Of the larger firms which supply cushions for various models, Hinson was distinctly unhelpful and I didn't even bother with Wiseco (due to similar responses in the past when making technical enquiries).
Yes, with this all too common attitude of being "Exceptional" I've found that many Yanks tend to be xenophobic !
I can try asking for this yank hates the bull shit lack of customer service u.s. companies will give towards international buyers. They tell you to contact your local distributor?