facebook1   youtube1   twitter1   instagram   linkedin1   pinterest1

logosmallNOTICE:  If you are not a free registered member of the site, you will not see the photos in the forum, and you won't be able to access our premium member content. Please consider joining our community!

Clutch pressure plate contacting side cover

28 May 2019 17:30
MarkT
Site Supporter
Site Supporter
Posts: 5842
More
Clutch pressure plate contacting side cover #11
The other thing you mentioned was not understanding the clutch adjustment.

There are sort of two adjustments. The most important is the "internal free play". The lever on the engine has to be able to rotate a little before the flat hits the pushrod and starts moving the clutch. Best way to verify is to completely remove the cable... you should be able to rotate the engine lever a little by hand before it hits the internal pushrod and becomes really hard (impossible) to turn by hand.

The second adjustment is the cable free play.

No amount of cable free play can make up for not enough internal free play.... having no internal free play will cause clutch slipping and could allow the clutch lever to move the pressure plate further than intended... possibly causing rubbing.

Also on your model Yamaha calls for a "minimum distance" measurement with the clutch pulled... if you are less than this distance the engine lever has rotated too far and might cause a problem like you're having.

1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250

Please Log in or Create an account to join the conversation.

28 May 2019 18:29 28 May 2019 18:31 by tricky.
tricky
Mini Enduro
Mini Enduro
Posts: 23
More
Topic Author
Clutch pressure plate contacting side cover #12
Thanks for all of the replies! @MarkT, I am using an aftermarket gasket of what I would call typical thickness. But it could be the OEM gasket is slightly thicker?

Today I pulled the clutch and took a lot of photos!

To start, this is how the clutch was:
(Seems to be well meshed with the primary drive gear)



Here you can see the wear from the pressure plate on the inside of the engine case:


The pressure plate face has worn down around the 3 arrows and the center stub:


To start, the springs:
Each measured in at around 36mm



The inside of the pressure plate:


With the pressure plate removed:


Push rod and ball bearing removed:


The clutch boss, in the order it was on the shaft (left to right):
Washer, boss, washer, lock washer, nut


Clutch and friction plates removed:




Friction plates measure in at approximately 3mm, clutch plates come in at approximately 1.8mm



All plates combined come in at around 31mm, which makes sense. 7 friction plates and 6 clutch plates -> (7x3mm) + (6x1.8mm) = 31.8mm


To the best of my knowledge, this followed the parts drawing for the clutch assembly. Does anyone see any glaring issues?

Please Log in or Create an account to join the conversation.

28 May 2019 18:37
tricky
Mini Enduro
Mini Enduro
Posts: 23
More
Topic Author
Clutch pressure plate contacting side cover #13
I see in the OEM service manual that clutch plate thickness should be 1.2mm. At my measured ~1.8mm, that would put me out a total of approximately 3.6mm over 6 clutch plates. Maybe this is the issue?

Does anyone else have experience with EBC's clutch kit for the DT?

Please Log in or Create an account to join the conversation.

28 May 2019 19:50
MarkT
Site Supporter
Site Supporter
Posts: 5842
More
Clutch pressure plate contacting side cover #14
Beautiful pictures! :OnFire

I think you might be on to something regarding the thickness of the "steels"... Do you have the originals to measure?

(Yamaha used the same "design" and "size" of plates on many bikes, even modern ones. They did sometimes change the thickness of the friction or steel plates.)

I hope one of the experts here will have the answer for you!

:Buds

1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250

Please Log in or Create an account to join the conversation.

28 May 2019 23:40 28 May 2019 23:46 by RT325.
RT325
Collector
Collector
Posts: 4119
More
Clutch pressure plate contacting side cover #15
I Think, what ya going to have to do is remove one fiber then sit the pressure plate on & bottom it out then measure the gap left--or even better if there's no gap but i doubt it. If it doesn't reach then measure the gap & add a bit to allow for pressurizing the stack of plates then come up with a plan. With new plates it'll be ok minus one. Might just find two steels together is good enough to fill the gap. Of course you'll need to back the cable right off & let the arm go right back so the pushrod isn't getting in the way. Also, with problem you have i'd be a little worried how far on the driving splines the pressure plate is & it's a wonder they're not coming off the end with the clutch pulled in to cover bulging point. Springs would probably keep it in line to a point when not under driving force just with clutch pulled in like in neutral jut to watch the cover bulge. Early 250/360's weren't splined anyway. My maths are terrible but if--aghh, i can't do it. Ok--if a steel & friction are 4.8 & you're 3.6 over original with all the plates together--then minus one friction would put you 1.8 over 'if you left the steel as last plate in'. Springs would still be ok as 1.8 more compressed than original. That's if i got the fiber plate right at 3mm? No-one's added an extra steel before you bought it?, doesn't appear so in your pics--good pics too.

Please Log in or Create an account to join the conversation.

28 May 2019 23:49 28 May 2019 23:50 by RT325.
RT325
Collector
Collector
Posts: 4119
More
Clutch pressure plate contacting side cover #16
alternatively, can you get away with a bit of machining of the pressure plate where it's touching & get rid of that 'tit' in the middle too. Double gaskets, or make a super thick one--god i hate making gaskets.

Please Log in or Create an account to join the conversation.

29 May 2019 06:34
JayJay
Novice
Novice
Posts: 34
More
Clutch pressure plate contacting side cover #17
I would just take a friction and a steel plate off. That will only make you 1.2 mil short. or you could leave the steel and that will make you .6 mil over. Maybe it's a bad thought but I think it would be better to be under by a mil then to be over at all. but in no way would i make a 3mm gasket over stock. Too much room for failure there.

Please Log in or Create an account to join the conversation.

29 May 2019 06:58
tricky
Mini Enduro
Mini Enduro
Posts: 23
More
Topic Author
Clutch pressure plate contacting side cover #18
I think I have the original plates still... somewhere in the garage. I'll check and see if they come in at 1.2mm. If so - is there any reason not to mix the new EBC friction plates (which are the appropriate 3mm) with the (presumably) OEM steel clutch plates?

If that is a no-no, I could either try removing plates like JayJay and RT325 have hypothesized, or maybe mic my old OEM friction plates and see if they still have life in them - and just go with the original clutch until I get it figured out properly

Thank you all again for the input!

Please Log in or Create an account to join the conversation.

29 May 2019 07:16
MarkT
Site Supporter
Site Supporter
Posts: 5842
More
Clutch pressure plate contacting side cover #19
I can't remember ever changing the OEM steel plates unless they were warped or severely damaged. I'm actually surprised you found a kit that includes the steels... usually it's only the frictions that are sold.

You can use the OEM steel plates with the EBC frictions if they are still flat.... and very rare for me to find a warped one.

1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
The following user(s) Liked this Post t-bone, JayJay

Please Log in or Create an account to join the conversation.

29 May 2019 09:01 29 May 2019 09:04 by Pillsbury.
Pillsbury
Site Supporter
Site Supporter
Posts: 646
More
Clutch pressure plate contacting side cover #20
It looks like you have all assembled quiet well. I think you found your problem. :likey Just a suggestion. Take your old steel plates and rub them on full sheet of 180-220 grit sand paper on each side (lay the sand paper on a flat surface), they should be just fine. I've use just the garage floor with no sand paper also :) You're just trying to rough them up a bit when you do this.

1970 DT1-C Grand Prix race bike
1970 DT1-C Street tracker
1968 Honda CL90
1971 Honda Sl 125
1973 Honda CR250
1974 Honda MR-50
1966 Triumph Tiger Cub
1967 Moto Guzzi V700
1970 Suzuki TC90
1947 Mustang

Please Log in or Create an account to join the conversation.

Moderators: VinnieDEETyamadminDmanEnduronutMakotosunDevinJames Hart