peasie Posted September 16, 2010 Report Share Posted September 16, 2010 (edited) : Edited May 30, 2011 by peasie Quote Link to comment Share on other sites More sharing options...
jse Posted September 16, 2010 Report Share Posted September 16, 2010 Been out today on my txt 280 2001 and when i stopped with the clutch pulled in it went into reverse gear???The only way to get it going forward was to kill the engine and kick it over again and then it was fine for a while but just now and again if i stopped with the clutch pulled in,it went into reverse again. Any idea's please as i'm a bit worried!! Cheers Steve That's really unusual, but I'd first look for a sheared Woodruff key in the flywheel hub allowing the timing to change radically. Jon Quote Link to comment Share on other sites More sharing options...
smalley250 Posted September 17, 2010 Report Share Posted September 17, 2010 Yep it sits in the crank and sits prowd so to accomodate the the flywheel which has a grove. I would use thread lock when you do refit the new key. Quote Link to comment Share on other sites More sharing options...
gjbiker Posted September 17, 2010 Report Share Posted September 17, 2010 Hi do you think this could cause the reverse gear situation a sheared woodruff key? A simple(ish) explanation- The woodruff key aligns the flywheel to the crank and determines the ignition timing. If the key shears then the timing can shift causing the ignition to spark at the wrong time. If the sparks occurs to early as the piston is on the up stroke then the detonation can 'throw' the piston back down instead of it continuing on its normal rotation. This can then lead to the engine running in reverse which in turn causes to gearbox to run in reverse etc etc. Solution; Remove flywheel (you will require the correct tool for this) Remove the two broken halves of the woodruff key (usually found in the relative slots on the crank and flywheel) Fit new woodruff key Replace flywheel etc Move forwards (hopefully) GJ Quote Link to comment Share on other sites More sharing options...
smalley250 Posted September 18, 2010 Report Share Posted September 18, 2010 If the woodruff key has gone you may not need a flywheel puller as i leant the bike over and slight tap and of it fell. Gjbiker is right it is most likely the cause of your problems. Quote Link to comment Share on other sites More sharing options...
jse Posted September 22, 2010 Report Share Posted September 22, 2010 Well new woodruff key came (gas gas uk) and it is much smaller than the one i took out lengthwise rang to ask if i had wrong one sent and thats all they have.I am now wondering if the one i took out has been made as its a different material to the one gas gas uk sent, has anyone got the correct measurements of the correct woodruff key for a txt280 2001 model??? Cheers again Steve Got one out of parts and measured it: 3mm wide 15.3mm long 5.9mm tall Jon Quote Link to comment Share on other sites More sharing options...
gjbiker Posted September 25, 2010 Report Share Posted September 25, 2010 Strange one? I suppose if the stator backing plate was loose enough it may have the same effect on the timing as a slipping rotor? More details and a photo or two would be handy.......... GJ Quote Link to comment Share on other sites More sharing options...
amister Posted September 29, 2010 Report Share Posted September 29, 2010 Been out today on my txt 280 2001 and when i stopped with the clutch pulled in it went into reverse gear??? The only way to get it going forward was to kill the engine and kick it over again and then it was fine for a while but just now and again if i stopped with the clutch pulled in,it went into reverse again. Any idea's please as i'm a bit worried!! Cheers Steve Hello Steve. I am having the same problem with 2002 txt pro. I damaged my stator had it repaired wired everything back together took it for a ride, everything ran great, stopped to talk with a friend started it back up and low and behold I took off on reverse. I have checked my woodruff key and it is in good condition. I called a shop and they said it was probably my stator causing it to spark at the improper time. I have yet to check the ohms values to make sure they in in spec but I thought the voltage regulator controlled the output of the spark. If you find out anything will you please let me know and I will do like wise for you. Thanks Amos Quote Link to comment Share on other sites More sharing options...
jse Posted September 30, 2010 Report Share Posted September 30, 2010 Hello Steve. I am having the same problem with 2002 txt pro. I damaged my stator had it repaired wired everything back together took it for a ride, everything ran great, stopped to talk with a friend started it back up and low and behold I took off on reverse. I have checked my woodruff key and it is in good condition. I called a shop and they said it was probably my stator causing it to spark at the improper time. I have yet to check the ohms values to make sure they in in spec but I thought the voltage regulator controlled the output of the spark. If you find out anything will you please let me know and I will do like wise for you. Thanks Amos Hi again Amos, Jon here. I doubt the stator had anything to do with it as it's just a power generating device and no timing of any sort is involved. In unusual cases, the CDI can cause a retarded spark, which could lead to reverse running (spark close to TDC), but that's pretty rare in my experience. I'm no expert in the inner workings of the CDI system but maybe someone with a BSEE or MSEE can give us a clue as to the possibilities within the CDI or other components possibly causing the reverse running. Jon Quote Link to comment Share on other sites More sharing options...
sting32 Posted September 30, 2010 Report Share Posted September 30, 2010 (edited) Hi again Amos, Jon here. I doubt the stator had anything to do with it as it's just a power generating device and no timing of any sort is involved. In unusual cases, the CDI can cause a retarded spark, which could lead to reverse running (spark close to TDC), but that's pretty rare in my experience. I'm no expert in the inner workings of the CDI system but maybe someone with a BSEE or MSEE can give us a clue as to the possibilities within the CDI or other components possibly causing the reverse running. Jon Jon, (or anyone) correct me, but can you mannipulate the timing, by changing the degree in which the stator plate is installed on the older txt engines? I know the pro has the induction/flywheel location pickup pretty much unadjustable mounting since no longer on the stator, but I am not sure about the older bike engines. on older points type bikes you moved the stator to adjust timing, what about the TXT engines? Where is the pickup for flywheel position, isnt it on that stator plate as well? Looking at the old parts manual on GG-ES pages, looks like slotted holes to mount stator? Edited September 30, 2010 by Sting32 Quote Link to comment Share on other sites More sharing options...
amister Posted October 1, 2010 Report Share Posted October 1, 2010 Hi again Amos, Jon here. I doubt the stator had anything to do with it as it's just a power generating device and no timing of any sort is involved. In unusual cases, the CDI can cause a retarded spark, which could lead to reverse running (spark close to TDC), but that's pretty rare in my experience. I'm no expert in the inner workings of the CDI system but maybe someone with a BSEE or MSEE can give us a clue as to the possibilities within the CDI or other components possibly causing the reverse running. Jon Thanks Jon. Do you think I could have wired anything possibly incorrect? If you wire the the stator incorrect will it generate spark? The only thing I can think of is I either wired it incorrectly or the the stator is having issues. Could I have damaged the cdi by wiring it incorrectly? The one thing I do remember while I was wiring it up for the fist time was the woodruff she was sheared off i've since purchased a new one and the reverse problem occurred after that. Thanks Amos Quote Link to comment Share on other sites More sharing options...
jse Posted October 1, 2010 Report Share Posted October 1, 2010 Thanks Jon. Do you think I could have wired anything possibly incorrect? If you wire the the stator incorrect will it generate spark? The only thing I can think of is I either wired it incorrectly or the the stator is having issues. Could I have damaged the cdi by wiring it incorrectly? The one thing I do remember while I was wiring it up for the fist time was the woodruff she was sheared off i've since purchased a new one and the reverse problem occurred after that. Thanks Amos Amos, I'm guessing the stator is good as you have enough output to develop spark. I'd take your time and double check your wiring job against the wiring diagram. Usually the CDI wiring is "plug and play" as the connectors only go one way in most instances. Jon Quote Link to comment Share on other sites More sharing options...
jse Posted October 1, 2010 Report Share Posted October 1, 2010 Jon, (or anyone) correct me, but can you mannipulate the timing, by changing the degree in which the stator plate is installed on the older txt engines? I know the pro has the induction/flywheel location pickup pretty much unadjustable mounting since no longer on the stator, but I am not sure about the older bike engines. on older points type bikes you moved the stator to adjust timing, what about the TXT engines? Where is the pickup for flywheel position, isnt it on that stator plate as well? Looking at the old parts manual on GG-ES pages, looks like slotted holes to mount stator? The stator/trigger position on the older engines can be changed to a degree limited by the slots on the mounting plate. The Pro has a fixed stator plate and "external" trigger, which can be changed slightly by slotting the mounting plate holes. Most ignition timing adjustments now are carried out by the electronics. An early version of the Pro CDI had a programmable ignition system that required a wiring harness and laptop (and infinite possibilities of developing maps) but the current systems have two timing maps pre-programmed into the CDI module that are toggled by a switch on the bars. Jon Quote Link to comment Share on other sites More sharing options...
sting32 Posted October 1, 2010 Report Share Posted October 1, 2010 The stator/trigger position on the older engines can be changed to a degree limited by the slots on the mounting plate. The Pro has a fixed stator plate and "external" trigger, which can be changed slightly by slotting the mounting plate holes. Most ignition timing adjustments now are carried out by the electronics. An early version of the Pro CDI had a programmable ignition system that required a wiring harness and laptop (and infinite possibilities of developing maps) but the current systems have two timing maps pre-programmed into the CDI module that are toggled by a switch on the bars. Jon That is why I asked, I was thinkin if he didnt get stator tight, or aligned exactly where it came off... that it could be advanced. I was just thinking out loud, if like me last bike before the new fangled stuff, had points ya know, might not known... FWIW, I had bultaco that would run backwards, when timed badly by us, if you bumped the tree just right, and it happened on a riverbank (deep river too) when that happened. luckily it throws you over the bars when it did that, Scary stuff. lol Quote Link to comment Share on other sites More sharing options...
jse Posted October 1, 2010 Report Share Posted October 1, 2010 That is why I asked, I was thinkin if he didnt get stator tight, or aligned exactly where it came off... that it could be advanced. I was just thinking out loud, if like me last bike before the new fangled stuff, had points ya know, might not known... FWIW, I had bultaco that would run backwards, when timed badly by us, if you bumped the tree just right, and it happened on a riverbank (deep river too) when that happened. luckily it throws you over the bars when it did that, Scary stuff. lol Yep, I also remember the Bultaco days. Stuck up high on a steep muddy bank and starting to roll backwards one quickly finds out there is no way possible to get off/away from the bike and you're just along for the ride to the bottom..... Jon Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.