[Otto_Ing]

Glad a new engine got sorted for you Pete, that's still something. 

[Aus.GT]

That's good news Pete, Keen to hear the report when you get it.

oTTo have you checked out the IWIS/JWIS chains over there?

[Otto_Ing]

That's good news Pete, Keen to hear the report when you get it.

oTTo have you checked out the IWIS/JWIS chains over there?

Nope, I haven't had the clutch side open . I don't know enogh about the chain yet.

[adamGT]

Pete, from one biker to another, that is a terrifying occurrence. I'm glad you made it upright!

Please keep us up to date on this issue as I'm now questioning my bike. Thanks for making this a matter of attention!

[gashousegorilla]

   That is good to hear Pete.  I'm glad they are getting you a new motor.  Do let us know the results if they tell you. 

[Ariel Red Hunter]

A primary chain lives in an oil bath enviornment.  In my 70 years of motor-cycling, I have never heard of or experienced a primary chain having tight and loose links in it.  Final drive chain yes, primary drive chain, no.  I think the problem lies within the automatic tensioner.  There have been many issues with auto tensioners on ohc engines, and H-D's with chain drive to the cams.  A screw adjustable tensioner avoids this problem.  One sets the tensioner so as to have 3/8's to a half inch of slack, and, as long as there is clean oil in the chaincase, it's good for thousands of miles.  On BSA's and Triumph's, there was a port on the top run of chain to check tension, and an adjusting screw on the outside bottom to set the tension.

[Jimmy1]

 Hi All,
 I have been watching this post with fear!  My GT has had all of the usual issues now all resolved and since reading this post decided not to use it till further investigation. The one part of Pete's story that had me thinking was that when he pulled in the clutch nothing happened. I may be missing something here but to my mind even if the primary chain broke and seized the clutch basket, if the clutch was was pulled in it should still disengage?
 Anyhow I took the case off yesterday and had a good look at alignments etc and mine has no damage or signs of wear to the chain, the tensioner pad has a couple of minor wear grooves across it which I would expect and the chain is not stretched. Alignment of gears is good.
  A scary point to note was that when I put a socket on the clutch central retaining nut, it came undone with just the weight of the wrench! It is a nylock nut but the nylon has hardened and is not gripping the thread.  The crankshaft sprocket bolt was a little tighter but not much.
 To those with the know how I would recommend checking these 2 items. I have refitted both with loctite and torqued down. 
 I am thinking that if the clutch nut came loose it would allow lateral movement of the basket which could compromise the chain? Indeed looking at Pete's photo his clutch release bearing is out of its socket and the central nut behind seems to be closer to the release bearing than it should be? could just be the angle of the dangle.. But if the nut suddenly spun out on the shaft, it could maybe stop or restrict the disengagement of the clutch? + of course allowing sudden misalignment of the sprockets and a fatal chain event.
 This is a theory only so now I'll pass it over to the experts....

[Arizoni]

I agree with your thoughts.
If the clutch nut backed off, the misalignment of the clutch could cause problems with the primary chain.
Also, the problem with the lock nut should be looked into by owners of the CGT.

Nylock fasteners should not have any problem in the environment the clutch lives in if they were of good quality.
I wonder what sort of nylock nuts the Indians are making that would fail the way yours did?

[Otto_Ing]

...my thoughts too, the misalignment is more likely to cause the required force to snap the chain than the chain tensioner. A close look at the broken link, chain and teeth should give evidence.

[gashousegorilla]

Hi All,
 I have been watching this post with fear!  My GT has had all of the usual issues now all resolved and since reading this post decided not to use it till further investigation. The one part of Pete's story that had me thinking was that when he pulled in the clutch nothing happened. I may be missing something here but to my mind even if the primary chain broke and seized the clutch basket, if the clutch was was pulled in it should still disengage?
 

   You would think ?   But..... What does the inside of Pete's left side cover look like ?    He pulled the clutch and nothing happened or it just "hung there" , I believe he said .    Ummmm..... I wonder if the grenaded chain took out the linkage and spring which connects the clutch cable to the push pad ?   If that were not operational... pulling the clutch lever would do nothing.  What bothers me about Pete's pictures is.... why does it appear that the clutch gear is inboard of the sprag gear ?

[gashousegorilla]

That's a fair comment GHG, without having a look one might be able to modify the existing tensioner as you mention with a spring. I noticed the brand on the chain from the above pics is a Rolon Chain, Don't know what the quality is like?

  Ahhhh... what the Hell ?  I'm bored and it only takes a few minutes to pull the cover and primary. And this has ben on my mind.   Same brand chain between the Bullets and the GT's it appears.  "Rolon"  stamped on the link.  I have been thrashing mine for about ...  At least six years now ?    MAYBE, a few of the GT guys were unfortunate enough to get ones with a bad swage on a link pin perhaps ?

  Looking at this primary.... and providing everything  was made or machined correctly at the factory... there ain't a lot in here that would cause much of a mis-alignment.  The spacer behind the sprag gear ..IF.. flipped around back words, would only cause a mis-alignment of .75mm  on my bike.  Do a few of the GT's have a spacer that was machined too thick, causing a mis-alignment ? .... Maybe ?

  With the clutch assembled on the main shaft... and the nylock nut and washer tightened down.  There is only about two or three exposed threads sticking through that nut.   Looks pretty damn close to what Pete has there in his picture ?   And that space is determined by a main shaft collar which sits behind the clutch assembly.  It sits proud of the case about 1.5 mm.  Was that collar thickness machined correctly ?    It at least looks like it was in his picture, because of the amount of exposed thread sticking through the nylock nut.

  If the nylock nut were to be loose on the end of the main shaft .....   There.. IS .. a decent amount of in and out play on that shaft , with the nut completely removed .  BUT...  when the nut is in place and tightened down, there is no play.  IF.... the nut were to be a little loose ?  Not much in and out play would be involved , or mis-alignment , or separation between the clutch stack and the clutch basket/gear.  Remember... there is only two or three exposed threads on that shaft and if the nut were to be loose a full turn, we're only talking about a 1 mm here with the tread pitch on that shaft.  I would think it would take the nylock nut completely spinning off of the end of that main shaft, to cause any kind of significant play or mis-alignment ?

 If the the nylock nut were to spin off the end of the shaft ?   It would be caught around and spinning  on the push pad shaft.... the push pad/ bearing and cup assembly would bottom out inside the cover on the clutch linkage pin , and prevent the clutch assembly from separating ....   Anyways, that's what I'm seeing here.


    Some pictures for comparison purposes....

[gashousegorilla]

   The nylock nut, tightened down on the main shaft... only a couple/few exposed threads.

  And a shot of the crank and mains shaft's, with the sprag gear spacer and shaft collar in place.... orientated the way they should be.

[gashousegorilla]

  Some close ups of that sprag gear spacer... 

First picture is  " That side IN towards the motor"

 Second picture is " That side OUT towards the left side cover"

 

[gashousegorilla]

  And a couple shots of the inside of the left side cover , showing the linkage pin and spring, with and without the push pad/ cup and bearing installed. 


 

[gashousegorilla]

...