oakworth jon Posted November 2, 2007 Report Share Posted November 2, 2007 (edited) I have replaced the stator which had gone ('04 Rev3 250) and put everything back together. Bike ran great for about 2 min then died. On investigation the flywheel had come loose and has sheared off the locating key on the crank. I am not sure how this has happened as I tightened it fully (it was lifting the bike of the ground). Anyway...after speaking to Lampkins it appears that I have sheared of the top of the woodruff key, so have ordered a replacement. Does anyone have any advice/tips on how to remove the remaining part of the key (still in the crankshaft) and fit the new one? Also any advice on how the flywheel came loose, I am convinced it could not have been tightened any further...is there a trick I am missing? I don't want to rebuild the whole thing and then have the same happen again! Any advice gratefully received. Thanks, Jon. Edited November 2, 2007 by oakworth jon Quote Link to comment Share on other sites More sharing options...
paul w Posted November 2, 2007 Report Share Posted November 2, 2007 use a freshly sharpened "pin punch" and lightlly tap at one end of the woodruff key at about 45 degrees , this should "slide" the broken bit out. you will need to check for scoring on the crank and the inside of the flywheel, as a high spot will prevent it fitting correctly. small blemishes can be removed by lapping in the flywheel using light grinding paste. good luck. paul. Quote Link to comment Share on other sites More sharing options...
stevel Posted November 2, 2007 Report Share Posted November 2, 2007 As paul w says it is a woodruff key which is half round so his method is spot on. As for tightening, I pop down to my local garage and get them to tighten the nut with their impact wrench, and after I learned the hard way like yourself, I've never had a problem since Good luck Quote Link to comment Share on other sites More sharing options...
oakworth jon Posted November 2, 2007 Author Report Share Posted November 2, 2007 Thanks for the advice guys! I will give it a go. One more thing... What's the best way to lock the crank whilst doing up the nut? The best method I found was to put it in gear and lock the back wheel (bar through sprocket/swingarm). As I tightened the nut the rear shock compressed until it felt like it would explode! There must be an easier way? Quote Link to comment Share on other sites More sharing options...
stevel Posted November 2, 2007 Report Share Posted November 2, 2007 John, If you use an impact wrench you will find that just putting it in gear will be sufficient to stop it rotating, the impact action of the wrench will do the rest! Quote Link to comment Share on other sites More sharing options...
blocky Posted November 2, 2007 Report Share Posted November 2, 2007 That will almost certainly be the reason why the nut came loose. The springyness introduced through the drive train prevents the nut from being done up correctly. You MUST hold the flywheel whilst doing up this nut or it WILL come loose. Quote Link to comment Share on other sites More sharing options...
mtwallet Posted November 2, 2007 Report Share Posted November 2, 2007 as blocky says you must hold the flywheel when tightening the flywheel nut,if you hold the other half of the crank(by means of jamming in gear)whilst tightening,you risk the chance of knocking the crank out of true which can be an expensive mistake Quote Link to comment Share on other sites More sharing options...
bilco Posted November 2, 2007 Report Share Posted November 2, 2007 Have you got two hole's either side on the face of your flywheel,if so get a couple of longish bolt's or something like that,that fit's into the hole's,then get something like a nice long tyre lever,put tyre lever in between two bolt's and jam other end of lever under foot rest take up play of flywheel,then get your torque wench and tighten to correct tightness. Quote Link to comment Share on other sites More sharing options...
barrybaines Posted November 2, 2007 Report Share Posted November 2, 2007 Have you got two hole's either side on the face of your flywheel,if so get a couple of longish bolt's or something like that,that fit's into the hole's,then get something like a nice long tyre lever,put tyre lever in between two bolt's and jam other end of lever under foot rest take up play of flywheel,then get your torque wench and tighten to correct tightness. Was hesitant to reply to this as I couldn't remember exactley what I done BUT I do know I used a pair of Suzuki Bandit "dog bones" (suspenion links) as a "V" bolted to the flywheel and wedged them somewere may have been onto the jack stand. The same could be done with two lengths of steel two bolts that will fit the flywheel weight bolt holes another pinch nut and bolt for the two bits of steel and the floor? Quote Link to comment Share on other sites More sharing options...
ron Posted November 2, 2007 Report Share Posted November 2, 2007 DO NOT PUT ANY BOLTS THROUGH FLYWHEEL !!!!!!!!!!!!!!!!!!!!!!!! YOU WILL MOST CERTAINLY BE BUYING A NEW STATOR IF YOU DO !!!!!!!!!!!!!!!!!!!! JUST AS THE BOYS HAVE SAID USE AN AIR IMPACT TO TIGHTEN !!! YOU CAN NOT GET TIGHT ENOUGH WITH A WRENCH!! SCREWING BOLTS THROUGH THE FLYWHEEL WILL ONLY COST YOU ALOT OF MONEY.. Now I have your attention , best of luck .. a woodruff key is easy to chip if you do not line up correctly.. the flywheel will slide on nicely once lined up and use the air impact to tighten.. all should be well then .. My Best Ron Quote Link to comment Share on other sites More sharing options...
o.a.s motorcycles Posted November 3, 2007 Report Share Posted November 3, 2007 DO NOT PUT ANY BOLTS THROUGH FLYWHEEL !!!!!!!!!!!!!!!!!!!!!!!!YOU WILL MOST CERTAINLY BE BUYING A NEW STATOR IF YOU DO !!!!!!!!!!!!!!!!!!!! JUST AS THE BOYS HAVE SAID USE AN AIR IMPACT TO TIGHTEN !!! YOU CAN NOT GET TIGHT ENOUGH WITH A WRENCH!! SCREWING BOLTS THROUGH THE FLYWHEEL WILL ONLY COST YOU ALOT OF MONEY.. Now I have your attention , best of luck .. a woodruff key is easy to chip if you do not line up correctly.. the flywheel will slide on nicely once lined up and use the air impact to tighten.. all should be well then .. My Best Ron I don't think anyones talking about having bolts sticking all the way through into the stator you can put bolts in without winding them in that far. As has been said though an air impact driver is your best bet, even better if you've got one which you can set the torque on. Quote Link to comment Share on other sites More sharing options...
fkrisztian Posted November 3, 2007 Report Share Posted November 3, 2007 You can ride without the flywheel, until the impact wrench arrives. Quote Link to comment Share on other sites More sharing options...
bilco Posted November 3, 2007 Report Share Posted November 3, 2007 DO NOT PUT ANY BOLTS THROUGH FLYWHEEL !!!!!!!!!!!!!!!!!!!!!!!!YOU WILL MOST CERTAINLY BE BUYING A NEW STATOR IF YOU DO !!!!!!!!!!!!!!!!!!!! Well Blow me,I did'nt think i'd need to write the Idiot's version aswell.Anyway thank's for adding it im sure it will come in usefull for some person. Quote Link to comment Share on other sites More sharing options...
dan williams Posted November 3, 2007 Report Share Posted November 3, 2007 (edited) Ding! Alright everyone back to their neutral corner. Ron's right about putting the bolts through the flywheel. If the flywheel turns and they go roundy round they'll chew up the internals. The trick is to put them into the flywheel so they don't protrude through to the inside but connect enough threads in effect making a holding tool for the flywheel. To do this properly you need to make a plate that the bolts go through first that'll sit on top of the flywheel with a hole for the flywheel nut and a long handle. And if you don't use high grade bolts you can shear them off so spend the extra few coins. Don't rely on the clutch gearbox immobilizing the rear wheel method to get sufficient holding power on the flywheel to torque that nut. Any method that could counter the torque required to properly fasten the the nut risks breaking the case/gearbox and tweaking the crankshaft as this puts twisting force directly across the crank. You should be doing this with a torque wrench anyway. If you use a torque wrench it will become painfully apparent how little torque you are actually getting on the nut without directly holding the flywheel. Either make a holding tool proper or have a friend who's handy with metal work help you and get a good torque wrench so you know how tight it actually is. An air impact driver is great if you've got one but I don't and am not likely to get one. I do prefer the feel of assembly with a torque wrench but it has to be at least a 100 ft/lbs wrench to get the required torque. Not that 100 ft/lbs is the number you need to tighten to just that a wrench that will do that much torque is long enough to do the job. Ahhh leverage. Hey Ron, if anybody would know you would, what is the torque spec on the flywheel bolt? Of course the other option is to bring it to a dealer. Sorry if this sounds expensive but this is the equivalent of major surgery and the proper tools are essential to prevent complications. This is one case where you can do an awful lot of damage if you're not careful. Dan Edited November 3, 2007 by Dan Williams Quote Link to comment Share on other sites More sharing options...
oakworth jon Posted November 5, 2007 Author Report Share Posted November 5, 2007 Thanks everyone for the tips. Just letting you know I managed to borrow a compressor/impact wrench and it worked. For your info Lampkins told me 140NM for the torque. The wrench I used has no calibration so I went for the maximum and so far everything is fine apart from myself getting out of practise after the bike was out of action for months. I might get a get a flywheel 'holding' tool made so that I can do it properly if I ever need to do it again. I had to get one made to get the flywheel off in the first place. Jon. Quote Link to comment Share on other sites More sharing options...
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