broken clutch cover bolt new story


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7mmBR
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broken clutch cover bolt new story

Post by 7mmBR »

I tracked what I think may be a manageable oil leak to one of the lowest clutch cover bolt, broken off 2-3 threads beneath the mating surface. Enough to smoke on the pipes after 5 min running with 10W40. I gently snugged the others and could try to mitigate with 20W50....I have some experience removing small broken bolts in rifles but not aluminum. Guessing same approach but heck of a lot easier to stray from centre. My approach would be centre punch, centre drill and extract, maybe some heat too. Or is heli-coil the more likely outcome?Should be able to centre punch well before removing cover.feels like that's a through-hole which I think could help a lot, maybe could drill it through and tap for next size up
Last edited by 7mmBR on Sun Mar 08, 2020 8:34 pm, edited 1 time in total.

daves79x
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Re: broken clutch cover bolt

Post by daves79x »

Those do break sometimes. I've had good luck center-punching them, drilling until most of the threads are out, then tapping the remainder of the debris out. You can usually then just use the correct bolt and it wil tighten up OK.

Dave

7mmBR
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Re: broken clutch cover bolt

Post by 7mmBR »

Thanks, hate to admit it occurred to me you could drill it right through without removing cover and put a nut on the back! But I won't do that. But I will try to run this season without fixing it.

daves79x
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Re: broken clutch cover bolt

Post by daves79x »

It really is an easy fix. Think you could do it in under an hour.

Dave

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Re: broken clutch cover bolt

Post by CBX1000chris »

I've sometimes found the the broken bolt is a slack fit in the hole and with a scriber working on the end of the bolt, and patience, I can turn out the remains of the bolt. A little heat and penetrating oil helps get it started.
Chris.

7mmBR
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Re: broken clutch cover bolt

Post by 7mmBR »

thanks guys and rookie question here; I am assuming both suggestions imply removing clutch cover; if so do I need to drain engine oil and likely need a new gasket on hand? Thanks in advance

tevan
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Re: broken clutch cover bolt

Post by tevan »

New gasket for sure if I was doing it. If you put bike on side stand you will lose very little oil if any.

7mmBR
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Re: broken clutch cover bolt, new story

Post by 7mmBR »

Started to source gasket and cover bolt then double checked, brake cleaned and blasted air and rubbed dry, ran 'er and sure enough, NOT leaking from the clutch cover, but braids of oil cooler line are soaked. Removed another small cover to the rear and found a second cover bolt missing (this one deep stripped hole) so I sprayed and blasted and rubbed it all dry around there and ran 'er again, it's not leaking from cover. This time symptom was less, earlier I actually saw the oil line drip onto the pipe from lowest point, second time was less smoke but braids are saturated and it smokes when hot, Kerker is close there. So my question is do you often see these nice oil lines fail? Only 38 years old!

I poked all around the drain lines, don't seem related. Had to wonder but didn't think it was residue from massive cleaning I did a couple days ago, could have patched a doghouse roof with the tar I got from around the front sprocket and some of that mess had migrated to the centre stand so I was in there from the other side pretty heavy with citrus, scraping, air, some gel lube, but I didn't think I could have soaked the right side oil line....sounds like the oil line failing right? Braids are dry as you poke towards rear and higher from the low point of the line. I'll run it again tomorrow and see if symptom possibly alleviated, source of drip is harder to tell than one might think. Maybe it was some of that cleaning crap, come to think of it I wiped some residue off the floor there this morning. And the residue on the pipe from where drips were burning, seems to be maybe more than oil would leave. Now I'm thinking that cleaning stuff made it over there.....I'm 61 next week and squirming around with bifocals doesn't make it easier!

daves79x
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Re: broken clutch cover bolt new story

Post by daves79x »

Those old oil lines fail all the time. Replace the set ASAP. Terry (Tevan here) makes up new sets. But - you either have to pull the clutch cover or tilt the engine to change the right one. Perfect excuse to fix the broken/stripped bolt holes there.

Dave

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Re: broken clutch cover bolt new story

Post by 7mmBR »

Thanks Dave, that's great info. I used to adjust the valves on my CB750F 30+ years ago, but tilting the engine does not appeal to me yet, so clutch cover it will be!
PS this '82 is my first bike since 1987

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Re: broken clutch cover bolt new story

Post by 7mmBR »

I messaged Tevan but didn't realize my message was hanging in my "outbox". Meanwhile I found lines, gasket, bolts and a plug I needed elsewhere, all at one one place so I ordered them. Hope he's a member too; I tend to jump the gun sometimes when I want it done

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