sawtooth Posted October 11, 2009 Report Share Posted October 11, 2009 Can anyone post a pic of what a flywheel holding tool looks like? I sheared my woodruff key yesterday causing my bike to missfire and kick back when trying to start it, this resulted in part of my engine casing breaking to bits (Doh). After having repaired the damage ( Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 11, 2009 Author Report Share Posted October 11, 2009 Is this what i'm looking for? http://www.sammymillerproducts.co.uk/36 Quote Link to comment Share on other sites More sharing options...
chewy Posted October 11, 2009 Report Share Posted October 11, 2009 I.ve had that happen on a rev 3 as well... I lapped the taper with fine valve grinding past. (you could test the fit of the taper with engineers blue if youhave any experience of this method.. basically you put some colour on one of the components say the flywheel then you carefully line it up and push the flywheel onto the shaft taper and rotate it a turn carefully i.e keeping it perpendicular to axis if you get my drift) the colour will rub off where the highest spot is. If you'r going to BVM they do a flywheel puller for c. 1 Quote Link to comment Share on other sites More sharing options...
jse Posted October 11, 2009 Report Share Posted October 11, 2009 Can anyone post a pic of what a flywheel holding tool looks like? I sheared my woodruff key yesterday causing my bike to missfire and kick back when trying to start it, this resulted in part of my engine casing breaking to bits (Doh). After having repaired the damage ( Quote Link to comment Share on other sites More sharing options...
zippy Posted October 11, 2009 Report Share Posted October 11, 2009 I believe he wants a flywheel holding tool so that upon reassembly he can reliably hold the flywheel in place and use a torque wrench to tighten the nut to the proper torque setting. I have used a rubber strap wrench in the past. It worked once, but the next time I tried it no go, flywheel just spun. I am not real fond of the rope idea personally, I just don't like the idea of stuffing something into the cylinder that does not belong there. I also get concerned about stressing the head, head bolts/nuts etc. This is probably an unnecessary worry, but that's just me. Quote Link to comment Share on other sites More sharing options...
yamahaty250xox Posted October 11, 2009 Report Share Posted October 11, 2009 Dont bother with a holding tool. use a good ratchet gun and it will come off peice of piddle Quote Link to comment Share on other sites More sharing options...
zippy Posted October 11, 2009 Report Share Posted October 11, 2009 Oh and yes the backfiring problem was due to the woodruff key being sheared and the flywheel moving a bit on the shaft causing the timing to be out. Happened on my Sherco last winter. It was running great during a session of riding. Put bike away and took out 1 week later to ride, would not start and back fired a couple times. I checked the flywheel and the nut was super duper loose. The flywheel was still stuck to the shaft rather tightly but had spun on the shaft enough to mess up the timing. Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 11, 2009 Author Report Share Posted October 11, 2009 Top bombing guys, pretty much confirmed what i was thinking. Am clued up on lapping and engineers blue so will ensure a good fit on the taper. The rope idea sounds ok, as long is it wont damage anything? I'll knock up a tool tomorrow anyway though as i know i'll chicken out of putting the rope in the cylinder. Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 11, 2009 Author Report Share Posted October 11, 2009 While we're on the subject, the kicking back of the kickstart is a timing issue yes? My bike never did it untill yesterday when i sheared the key. Reason i ask is that a mate of mine got a bike a little while ago which does alot of kicking back when he starts it up, it runs ok other than that but maybe its worth looking at the timing as this isnt normal behaviour no? Quote Link to comment Share on other sites More sharing options...
jse Posted October 12, 2009 Report Share Posted October 12, 2009 Oh and yes the backfiring problem was due to the woodruff key being sheared and the flywheel moving a bit on the shaft causing the timing to be out.Happened on my Sherco last winter. It was running great during a session of riding. Put bike away and took out 1 week later to ride, would not start and back fired a couple times. I checked the flywheel and the nut was super duper loose. The flywheel was still stuck to the shaft rather tightly but had spun on the shaft enough to mess up the timing. I usually use a regular flywheel holder in the shop, but as I said, the rope will work in an emergency and, in fact, is easier on the internal parts as it acts like a cushion. A note on the taper: The tapers of the crank hub and flywheel hub are different. They are machined at a slightly different angle from each other (it's known as a ".001" interference fit" or a "Morse Taper") so they stick together, and why you need a puller to get them unstuck. When you lap the parts together, the interference fit is gone (the taper angles are now the same), so the parts are not as secure. As such, I'd add a little more torque valve (if torque setting is given in a range, say 38-42 Ft Lbs, use the higher number at least) and check the torque after a couple of heat cycles (riding sessions) as it will probably back off a little (which happens to new bikes if the flywheel fastener is not checked after a few rides). Sometimes, a little red Loctite ("non-serviceable" stud and bearing mount and a little heat to the fastener will break the Loctite bond if the flywheel needs to be removed) will add a little more security. Jon 1 Quote Link to comment Share on other sites More sharing options...
dan williams Posted October 13, 2009 Report Share Posted October 13, 2009 Couple bucks worth of flat stock, four drill holes, three bolts and a wing nut and some washers to make sure the screws all line up and don't dig into the stator coils. Cost about $5 and had no problem with all the torque I could throw at it. 1 Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 13, 2009 Author Report Share Posted October 13, 2009 (edited) Have made a holding tool but am not convinced about the taper using an interference fit. If the tapers were different angles then the contact surface area will be greatly reduced. Will look into it before lapping/grinding anything, everywhere i look so far tells me that the tapers should be lapped together and the holding force of the flywheel nut is what keeps the surfaces locked together. Will CMM a matching pair of tapers at work later and see what the angles read. Its not that i dont trust you but i want to be sure before i lap anything on the bike. What torque should the flywheel nut be? Edited October 13, 2009 by SawTooth Quote Link to comment Share on other sites More sharing options...
ham2 Posted October 13, 2009 Report Share Posted October 13, 2009 Couple bucks worth of flat stock, four drill holes, three bolts and a wing nut and some washers to make sure the screws all line up and don't dig into the stator coils. Cost about $5 and had no problem with all the torque I could throw at it. Confirmed ,in fact that could be my very own one in that photo (but it's not..) Quote Link to comment Share on other sites More sharing options...
sawtooth Posted October 13, 2009 Author Report Share Posted October 13, 2009 Anyone know what torque should be applied to the nut? Quote Link to comment Share on other sites More sharing options...
jse Posted October 13, 2009 Report Share Posted October 13, 2009 Have made a holding tool but am not convinced about the taper using an interference fit. If the tapers were different angles then the contact surface area will be greatly reduced. Will look into it before lapping/grinding anything, everywhere i look so far tells me that the tapers should be lapped together and the holding force of the flywheel nut is what keeps the surfaces locked together. Will CMM a matching pair of tapers at work later and see what the angles read. Its not that i dont trust you but i want to be sure before i lap anything on the bike. "Mating taper connections can be used for temporarily securing one item to another. One such taper connection is a Morse taper connection. Generally, a Morse taper is defined as a taper connection having a taper surface making an angle of about 2 to 12 degrees relative to the longitudinal axis of the component. Morse taper connections can be made between interpenetrating parts, with, e.g., a first of the parts having a tapered bore, and a second of the parts having a frustoconical shape for securement in the tapered bore of the first part. The tapered bore and the frustoconical shape can have slightly different sizes or taper angles to facilitate securement of the parts via the mating taper connection as described below. To assemble mating taper connections, including Morse taper connections, items having a mating taper structure are interference fit one to the other to cause cointegration or locking of the items. In some cases the cointegration results in material transfer across the zone of contact, i.e., cold welds." Jon Quote Link to comment Share on other sites More sharing options...
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