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Post by jloi on Oct 31, 2020 23:24:37 GMT -5
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Post by 190mech on Nov 1, 2020 1:38:48 GMT -5
A key should only shear if the flywheel nut is loose or the wrong taper,,Is that flywheel a genuine TGB part??With proper tapers,a key is not needed,lots of high end ignitions dont even have a slot machined in them..Post some pics of your iggy installation,maybe we can find something..
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vacationer
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Post by vacationer on Nov 1, 2020 17:32:55 GMT -5
Definitely not TGB but a very close fit. I'm trying to machine a new key out of an unused spacer - last ditch effort before trying to shop again.
I guess I thought if the taper wasn't exact, the stator+magnets would keep the magneto in place, but I didn't expect it to cause shearing. What kind of movement specifically causes shearing?
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Post by 190mech on Nov 1, 2020 18:09:02 GMT -5
A taper gets its great holding power through a precision fitment,if the 2 parts are off by 1 degree it has zero strength!A key is just there to position the flywheel to the crankshaft in a repeatable manner...
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vacationer
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Post by vacationer on Nov 1, 2020 19:35:44 GMT -5
Shite...well as of right now, everything is holding, but I don't expect it to last. This far along, to abandon the stator upgrade would be throwing away more money than I can stomach. Short of filling in the gap with an epoxy or something else shape-taking, I may be out of options. I did make up the extra space between the fywheel nut (where the threads ended) and the new flywheel using some rings made from rotary polishing pads. Worked better than expected.
I'll try and measure the gap and decide if a more elegant fix is available to me. I'm in too deep....
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Post by 190mech on Nov 2, 2020 5:06:51 GMT -5
Other than machining an adapter,your only option is to bin that one before the crankshaft gets ruined when the flywheel beats it to death!I have a few TGB cranks around here and can see if another brand crank has the same taper,,sorry no flywheel or stator here as I gave it to another member a few years back...
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Post by jloi on Nov 2, 2020 6:38:16 GMT -5
isn't the new stator itself ok ? and the flywheel > they're matched . isn't it just the "NO" key that is the problem ?
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Post by Steve B on Nov 2, 2020 9:45:49 GMT -5
insert code here Why can't you order the correct key from a parts list? Look at the numbers on you're engine and order it that way, if you cannot find it for you're specific bike, i am certain other scooters use that exact engine and woodruff key. If you send some pics and numbers i will try to help you.
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Post by Steve B on Nov 2, 2020 10:17:57 GMT -5
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vacationer
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Post by vacationer on Nov 2, 2020 11:16:05 GMT -5
Steve B wow what an incredible website. would have saved me some time over the past year. thank you! jloi I'm taking 190mech's comments to mean that my flywheel is inherently in conflict with my crank 190mech i definitely don't have the ability or know-how to machine an adapter. if i end up with no remaining options, i'll probably try jb weld + prayer, but that idea makes my stomach hurt. I also have my old flywheel, which of course fits the crank perfectly, but adapting that to the new flywheel also sounds way beyond my abilities
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vacationer
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Post by vacationer on Nov 2, 2020 11:27:34 GMT -5
Also, might this taper mismatch explain why it's so easy for me to remove the new flywheel without a flywheel puller?
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Post by 190mech on Nov 2, 2020 12:52:28 GMT -5
Was your old TGB stator a 4 pole?Perhaps we can find you a replacement since you have your old flywheel!
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vacationer
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Post by vacationer on Nov 2, 2020 13:26:14 GMT -5
It was indeed a 4-pole. However, I'd like to stare at my setup for a little while today and see if i can't come up with something. Be in touch.
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vacationer
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Post by vacationer on Nov 2, 2020 13:34:43 GMT -5
Anybody knowledgeable about the construction of flywheels? Namely the plate in the center with the circular tabs/caps/bolts/whatever-you-like that hold it to brass outer housing. I'm consider the feasibility of switching the old plate onto the new flywheel using my own bolts/nuts - assuming the parts are reasonably separable and minimal machining would be required. This way, the taper would be perfect match and I could keep my 8-pole.
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Post by geoffh on Nov 2, 2020 15:25:21 GMT -5
This is going to end in tears and a ruined crankshaft,your mismatched tapers is why it will pop on and off easily,that's not good,modifying the flywheels is interesting and a desert island kind of desperate fix,remember that lump of metal is doing 6/7k rpm.I have been in the motor trade for 50years as far as I know flywheels can be skimmed "a tad" ring gear replaced and bearing renewed,if you do try the taper/center repair I would keep your limbs and digits well away from it.
Geoof
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