Author Topic: 1971 GTR 350 Clutch Issues  (Read 761 times)

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Offline Bridgestoneboy

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1971 GTR 350 Clutch Issues
« on: December 19, 2017, 12:27:32 PM »
I am currently nearing the end of my restoration on a 1971 Bridgestone GTR 350. When I attempted to run the clutch cable for the bike I ran into a couple issues. I am hoping some of you may know what I am doing wrong or how to fix this. First, when running the cable and placing the clutch wire holder in between the crankcase itself and dust cover, there seems to be a lot of room for the cable to move side to side. Is this normal? The other issue I am having is when I attempt to place the ball that is shown in the manual in-between the clutch release arm and the release push rod, the ball prevents the push rod from sliding into the release arm and allowing for adjustment and prevents the top pressure plate on the clutch side of the engine from tightening down so the carburetor cover fits. Any help would be appreciated, thanks.

Offline BRT-GTR

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Re: 1971 GTR 350 Clutch Issues
« Reply #1 on: December 19, 2017, 05:30:51 PM »
               The clutch wire holder at the crankcase end wasn't one of Bridgestones finest designs ! :-\  They are a loose fit but it works and the clutch cable holds it in place.
            Check the diameter of the ball in the release arm, should be 1/4'', sounds like yours might be too big. Alternatively, check there isn't already a ball in the hole, not easy to see if it is well greased. Take the adjuster screw right out to view.

          Problem could also be the clutch outer pressure plate not being correctly lined up. See manual, small hole in the pressure plate has to line up with a small dimple on the clutch centre. This allows the teeth on the inside of the plate to line up with the slots on the clutch centre. Pressure plates sits on the centre hub if not lined up and stops the clutch from working.
           Hope this helps, come back to us if you are still having problems.        Brian.
         
« Last Edit: December 20, 2017, 01:30:52 PM by BRT-GTR »
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Offline davis

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Re: 1971 GTR 350 Clutch Issues
« Reply #2 on: December 20, 2017, 12:04:10 PM »
You may have already done this, but make sure the push rod moves freely enough. The rod lacks a proper seal at the chain side and I found that most of my engines needed a thorough cleaning of the shaft hole it goes through. I think many of these GTR's were used by young guns as scramblers which caused mud and water to pack into the push rod shafts and corroded the rods and shaft holes as well.

- Bob

Offline Bridgestoneboy

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Re: 1971 GTR 350 Clutch Issues
« Reply #3 on: December 20, 2017, 02:42:33 PM »
First off, thank you for the responses,
I doubled checked everything and it seems the issue is with the ball. The shaft hole seems clean and the ball is indeed a quarter inch. However when I put the ball in place, it does not allow the shaft to slide into clutch release arm, and the clutch release adjustment screw doesn't even touch anything . I'll attach pics to show you what I am talking about, but when the ball is in place, it pushes the shaft so far out the clutch side of the bike that I can't even get the plates on. However without the ball the system seems to work fine.  :o Thanks again. Casey

Offline BRT-GTR

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Re: 1971 GTR 350 Clutch Issues
« Reply #4 on: December 21, 2017, 08:26:52 AM »
   Casey,
           The ball should drop into the hole in the actuator spiral and sit against the inner end of the adjuster screw, does it ?   If not, has the hole somehow become burred ? That would expain why the adjuster screw is not touching anything.
  Just file or drill the burrs out.
   
      The thick end of the long push rod (236mm) then goes against the ball, thin end toward the clutch, then the 6x10mm spacer, then the clutch mushroom. Your clutch operation should now be OK.

     There could be other issues but lets take it one step at a time. We have seen homemade pushrods to compensate for missing clutch plates or odd mixes of plates.                  Brian.
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Offline Bridgestoneboy

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Re: 1971 GTR 350 Clutch Issues
« Reply #5 on: December 21, 2017, 10:12:33 AM »
 When checking the hole on the actuator, the hole is about .25in or 6.35mm. The hole does not look to be burred. The ball however is 7.92mm or 3.1in in diameter. The ball does not drop into the hole and rest against the adjustment screw.  I am puzzled as to how this was ever assembled in the first place if the ball was too big but something definitely seems wrong now. Thank you to all the help I have received so far.

Offline dcr

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Re: 1971 GTR 350 Clutch Issues
« Reply #6 on: December 21, 2017, 11:39:18 AM »
It's been a while since I had one of these apart, but doesn't the ball go in from the other side of the release arm?

Dan
1966 175 DT and 1968 350 GTR

Offline BRT-GTR

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Re: 1971 GTR 350 Clutch Issues
« Reply #7 on: December 21, 2017, 12:46:26 PM »
         I thought the ball looked slightly oversized, but you are confusing me now. In reply 3 above you stated the ball measured a 1/4 inch, which it should. Scrap the ball in the picture and find a quarter inch ball, cycle shop?, that will solve the problem.           Brian
« Last Edit: December 21, 2017, 12:55:18 PM by BRT-GTR »
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Offline Bridgestoneboy

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Re: 1971 GTR 350 Clutch Issues
« Reply #8 on: December 22, 2017, 04:25:01 PM »
The responses are helping greatly! I apologise if there was any confusion, response three I did a very very rough measurement and it wasn't until I really became curious about the ball size that I got out the caliper to get an accurate measurement. The ball is 3.1 in in diameter. An it does not look like there is any way of placing the ball in the actuator from the other side. This could be as simple as a mix up and the ball does not belong to this. I will update when I find a different ball and try again.

 


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