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flywheel/clutch removal


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StardusterToo
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flywheel/clutch removal

Sat Sep 14, 2013 11:51 pm » Post: #1 » Download Post

Getting on with the engine strip.. just a thought - before I remove the chain and drop the engine, is it a 'bad idea' to crack the torque on the flywheel/clutch bolts with the bike in gear ? Seems it might be easier than fighting with them on the bench..
Cheers
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gepe

 
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Sun Sep 15, 2013 9:42 am » Post: #2 » Download Post

I have thought about the same. I assume it depends on the torque you need to apply to loosen/tighten the bolts and nuts. I haven't looked into the details but just from guessing I would say the 5 clutch bolts don't need high torque but maybe the primary drive nut and the flywheel bolt need a torque well above what the engine would deliver to the transmission, therefore I would be hesitating to strain the transmission with that torque.
Details: Our bike delivers ~33 Nm max. torque (from factory). Acc. to Jamie's dreamgate webpage, the primary drive bolt needs 95 Nm when tightening, maybe more when loosening. That is roughly 3x the engine's torque. Make your own estimate whether the transmission is prepared to take that load.
Maybe my way of thinking is way to conservative but I tend to be quite careful in such cases. I have seen pictures of engine strip downs where rotation of the crank is prevented by blocking the conrod with a socket extension over a few wooden blocks. I wouldn't do that with my engine, the risk of deforming the conrod little end eye with such an undistributed load is IMO too high.

gepe.
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Moa
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Sun Sep 15, 2013 9:58 am » Post: #3 » Download Post

It's a bit easier to get the highly torqued bolts off while the engine is in the frame. I always jam the primary drive and clutch basket gears. I use a soft coin, but you can get a dedicated gear jammer or use a piece of soft metal. Or if you really want to be safe, get a clutch basket holder or flywheel holder.
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gepe

 
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Mon Sep 16, 2013 5:51 pm » Post: #4 » Download Post

Am I allowed to link to this tool? If not delete the post, please.
gear jammer:

http://www.iane.co.uk/store/paddock-and-workshop/tools/gear-jammer/prod_16.html
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Hobbit210

 
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Mon Sep 16, 2013 7:00 pm » Post: #5 » Download Post

The only problem with this method is that it is easy to make the crank 'out of true'. All the load that you are putting on the flywheel nut is being transferred along the crank with the distinct possibility of revolving (slightly) one or more of the journals.
If you intend to have a crank rebuild then it's possibly ok but a flywheel holding tool is by far the best (maybe only!!) method.

Mike
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gepe

 
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Tue Sep 17, 2013 6:00 am » Post: #6 » Download Post

Do you have a link to a flywheel holding tool for the NSR?
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StardusterToo
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Wed Sep 18, 2013 5:54 am » Post: #7 » Download Post

I think I'm just going to make one that fits into the holes in the flywheel. . I'll post some pics once it's done. . The reasoning behind not using the transmission is kinda compelling!
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Hobbit210

 
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Wed Sep 18, 2013 8:34 am » Post: #8 » Download Post

StardusterToo wrote:I think I'm just going to make one that fits into the holes in the flywheel. . I'll post some pics once it's done. . The reasoning behind not using the transmission is kinda compelling!


That's what I did. It worked ok for me...after bending a bit Rolling Eyes Rolling Eyes Better than than damaging the crank though!!

Have a look here for an idea on what to do: http://forums.everything2stroke.com/threads/40677-D-I-Y-Flywheel-Holder-Tool

Mike
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