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'68 DT1 Clutch Interference
- RT1
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Replied by RT1 on topic '68 DT1 Clutch Interference
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'68 DT1, '71 RT1, '71 JT1 (x2), '72 AT2 (x2), '74 DT250A, '75 XS650, '54 BSA C11G, '70 Honda CT70, '73 Hodaka Combat Wombat, '05 Moto-Guzzi Breva, '15 Triumph Tiger, +++
"We are mere custodians of mechanical things. Our job it to care for them, improve them and pass them on to others.” - Peter Egan
"We are mere custodians of mechanical things. Our job it to care for them, improve them and pass them on to others.” - Peter Egan
25 Apr 2024 11:30
#11
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- MarkT
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Replied by MarkT on topic '68 DT1 Clutch Interference
You might report how far the pushrod is sticking out of the end of the shaft? IIRC there's normally very little to no gap under the head of the pushrod and the end of the shaft
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
25 Apr 2024 12:30
#12
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- Wrench66
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Replied by Wrench66 on topic '68 DT1 Clutch Interference
I would start by pulling the clutch cover and then observing the clutch pack's movement as you work the lever. At least this will confirm it's NOT the cover
-- Ray
-- Ray
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25 Apr 2024 12:37
#13
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- RT1
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Replied by RT1 on topic '68 DT1 Clutch Interference
"You might report how far the pushrod is sticking out of the end of the shaft? IIRC there's normally very little to no gap under the head of the pushrod and the end of the shaft"
Mark - not following. The actuator side?
Ray - clutch operation has been viewed with side cover off and works beautifully. This is why I'm focused on the cover being the culprit.. When it goes back on, the clutch movement binds.
Nonetheless, I will be reviewing everything that's been mentioned to eliminate all other possibilities.
Mark - not following. The actuator side?
Ray - clutch operation has been viewed with side cover off and works beautifully. This is why I'm focused on the cover being the culprit.. When it goes back on, the clutch movement binds.
Nonetheless, I will be reviewing everything that's been mentioned to eliminate all other possibilities.
'68 DT1, '71 RT1, '71 JT1 (x2), '72 AT2 (x2), '74 DT250A, '75 XS650, '54 BSA C11G, '70 Honda CT70, '73 Hodaka Combat Wombat, '05 Moto-Guzzi Breva, '15 Triumph Tiger, +++
"We are mere custodians of mechanical things. Our job it to care for them, improve them and pass them on to others.” - Peter Egan
"We are mere custodians of mechanical things. Our job it to care for them, improve them and pass them on to others.” - Peter Egan
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- MarkT
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Replied by MarkT on topic '68 DT1 Clutch Interference
The pushrod in the shaft right under the spring-loaded clutch pressure plate. Looks like about a nickel size plate on the end of a rod. When you pull the lever it pushes against the pressure plate.
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
25 Apr 2024 14:21
#15
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- RT325
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Replied by RT325 on topic '68 DT1 Clutch Interference
I'm not up to date so will read later. But on a 360 if you use a narrower 250 cover the pressure plate will run into it--by memory.
Conversely, if you use the wider 360 clutch assembly on a 250 it will hit the 250 cover on actuating--by memory.
Lots of 'by memories' sorry but i've been through all that building parts motors from boxes of assorted motors mix n matching.
So if your motor has never run & was built from assorted parts--is it a possibility.
Or are you sorted now & i'm way behind haha.
Conversely, if you use the wider 360 clutch assembly on a 250 it will hit the 250 cover on actuating--by memory.
Lots of 'by memories' sorry but i've been through all that building parts motors from boxes of assorted motors mix n matching.
So if your motor has never run & was built from assorted parts--is it a possibility.
Or are you sorted now & i'm way behind haha.
25 Apr 2024 15:23
#16
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- SKYDANCER46
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Replied by SKYDANCER46 on topic '68 DT1 Clutch Interference
It won't be because of a thin aftermarket side cover gasket. I had one on my 68 and the clutch worked fine and didn't touch the cover with it. However I ended up replacing it with a NOS yamaha gasket because the thin aftermarket gasket leaked a bit after sitting a couple of weeks. The NOS Yamaha gasket was much thicker and more important (wider) so it covered the complete gasket area of the engine case and side cover.
I don't think it has anything to do with your clutch plates either or how you have them stack because you said when you pull the clutch lever is when the preasure plate hits the side cover? You can not pull the clutch lever all the way to the hand grip?
I would check the push crown under the preasure plate like Mark mention to make sure it's not sticking out to far from the clutch boss. Then be sure it's the correct one and check the push rod length/ball and the free play adjustment on the push lever assembly on the chain side cover.
You can use a thin layer of grease on the outer side of the preasure plate and center, then install side cover and pull the clutch lever in and see where the grease is on the inside of the side cover if its hitting it.
Here is a close up of the clutch. I think this picture is before taking it apart because the clutch plates look like the old stock plates. Again i don't think your plates are the issue since you said it only hits when you are releasing preasure on the clutch plates as you are pulling in the clutch lever.
You really need to confirm if and where the clutch preasure plate is hitting the side cover if that's actually happening.
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I don't think it has anything to do with your clutch plates either or how you have them stack because you said when you pull the clutch lever is when the preasure plate hits the side cover? You can not pull the clutch lever all the way to the hand grip?
I would check the push crown under the preasure plate like Mark mention to make sure it's not sticking out to far from the clutch boss. Then be sure it's the correct one and check the push rod length/ball and the free play adjustment on the push lever assembly on the chain side cover.
You can use a thin layer of grease on the outer side of the preasure plate and center, then install side cover and pull the clutch lever in and see where the grease is on the inside of the side cover if its hitting it.
Here is a close up of the clutch. I think this picture is before taking it apart because the clutch plates look like the old stock plates. Again i don't think your plates are the issue since you said it only hits when you are releasing preasure on the clutch plates as you are pulling in the clutch lever.
You really need to confirm if and where the clutch preasure plate is hitting the side cover if that's actually happening.
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1970 DT250C
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- RT325
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Replied by RT325 on topic '68 DT1 Clutch Interference
Just my thought now i've written the other post & changed computers to an efficient one.
The first plate in looks like it could go a lot further back, so whats stopping it.
Didn't DT1 have a strange setup using a thick unsplined spacer plate at the back between two normal steels & use one less fiber.
So if an aftermarket set of fibers are fitted maybe with an extra plate & sets it further out?? how do we end up??.
Think back in "68-ish i used to add a fiber where the spacer is & hang that on the wall.
Of course then the pressure plate will move over because the fiber will be thinner than that fat unsplined spacer steel & achieve or fix your distance when actuated.
But bottom line is so long as the pressure plate doesn't bottom on the center before doing it compressing job.
The first plate in looks like it could go a lot further back, so whats stopping it.
Didn't DT1 have a strange setup using a thick unsplined spacer plate at the back between two normal steels & use one less fiber.
So if an aftermarket set of fibers are fitted maybe with an extra plate & sets it further out?? how do we end up??.
Think back in "68-ish i used to add a fiber where the spacer is & hang that on the wall.
Of course then the pressure plate will move over because the fiber will be thinner than that fat unsplined spacer steel & achieve or fix your distance when actuated.
But bottom line is so long as the pressure plate doesn't bottom on the center before doing it compressing job.
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Replied by RT325 on topic '68 DT1 Clutch Interference
Ok it still shows 6 plates on fartzilla so i'm wrong but was a thought anyway so look in that area. I had the exact problem on my 360 using a 250 cover. All set to go & bugger me couldn't pull the clutch in. But thats getting off track.
www.partzilla.com/catalog/yamaha/motorcycle/1968/dt1/clutch
www.partzilla.com/catalog/yamaha/motorcycle/1968/dt1/clutch
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- RT1
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Replied by RT1 on topic '68 DT1 Clutch Interference
Good morning, all
I did some further investigating last night on this interference issue. Using my list of items to look over, here’s what I’ve found. Rod with “mushroom head” that pushes the pressure plate sits all the way down with a “clink” as it should. If it weren’t, I’d think that in turn the pressure plate wouldn’t be able to sit properly as it is. Here’s what I did last night….
ADDITIONAL: I can't post the pics!!!!
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I did some further investigating last night on this interference issue. Using my list of items to look over, here’s what I’ve found. Rod with “mushroom head” that pushes the pressure plate sits all the way down with a “clink” as it should. If it weren’t, I’d think that in turn the pressure plate wouldn’t be able to sit properly as it is. Here’s what I did last night….
- find & review service manual – done and good to have, but didn’t tell me anything I didn’t already know.
- measure all remaining discs, plates, & cushions – All pieces verified and measure as they should.
- check actuator adjustment – adjustment was perfect. Screw turned in till contact with rod then backed off ¼ turn and locked down. Basic stuff
- reassemble according to manual / parts diagram – done but manual not needed
- match reassembly to new skydancer46 photo (if possible) – wasn't necessary, but thank you
- add wet paint (or any better suggested marking material) to pressure plate, put cover on along with gasket and hope that clutch activation leaves a mark- Succes! Sort of. The exercise confirmed that the pressure plate center is contacting the small nub on the inside of the cover! See pic.
ADDITIONAL: I can't post the pics!!!!
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'68 DT1, '71 RT1, '71 JT1 (x2), '72 AT2 (x2), '74 DT250A, '75 XS650, '54 BSA C11G, '70 Honda CT70, '73 Hodaka Combat Wombat, '05 Moto-Guzzi Breva, '15 Triumph Tiger, +++
"We are mere custodians of mechanical things. Our job it to care for them, improve them and pass them on to others.” - Peter Egan
"We are mere custodians of mechanical things. Our job it to care for them, improve them and pass them on to others.” - Peter Egan
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