Wildguzzi.com
General Category => General Discussion => Topic started by: canuck750 on June 08, 2016, 10:32:46 PM
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Riding my V7 Sport last night at the end of the evening and close to home I suddenly felt a brief decelaration and a high pitch squeal, it felt like a brake grabbing but it was very short lived and then the generator light came on. I was only a couple blocks from home. When I got in the shop I looked around the bike and noticed what I though was a stone stuck to the alternator cover, turned out to be the end of a bolt coming through the cover.
(http://i249.photobucket.com/albums/gg217/canuck750/2016-06-07%2021.38.05_zps6uds5iwo.jpg) (http://s249.photobucket.com/user/canuck750/media/2016-06-07%2021.38.05_zps6uds5iwo.jpg.html)
I had set the timing on the weekend and rotating the alternator with an alan key socket I snapped the rotor bolt. I made a new rotor bolt from a stainless steel bolt, the First Mistake, then I did not use locktite, Second Mistake.
While riding the bike the rotor bolt worked loose, then along with the weight of the rotor the bolt cut through the cover until it jammed at which time is snapped the bolt, leaving a few mm of bolt in the crank. The rotor no longer tight to the crank worked free of the grasp of the oil seal and hot oil saturated the stator and rotor negating the charging system,
(http://i249.photobucket.com/albums/gg217/canuck750/2016-06-07%2021.51.32_zpsx91lsytn.jpg) (http://s249.photobucket.com/user/canuck750/media/2016-06-07%2021.51.32_zpsx91lsytn.jpg.html)
I should have waited for a proper steel rotor bolt and torqued it with locktiite. Stainless is too brittle and a lack of locktite proved fatal.
Sucks!
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Ouch! I've seen that several times over the last four decades! You're not Robinson Crusoe on that....... :angry:
Pete
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Yeah , not the first time that's happened Jim .
Dusty
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Well it's somewhat comforting to know it's not a unique mistake, the V7 Sport sure makes a great drill press!
Basically a flat headed fastener cutting through a couple mm of aluminum in seconds is pretty impressive!
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Well it's somewhat comforting to know it's not a unique mistake, the V7 Sport sure makes a great drill press!
Basically a flat headed fastener cutting through a couple mm of aluminum in seconds is pretty impressive!
How many drill presses rev to 5K revs ? :laugh:
Dusty
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Not the same thing, but In the vicinity . . .
(http://thumb.ibb.co/fqWhMF/timingcoverbroke1.jpg) (http://ibb.co/fqWhMF)
I made the hex key too long. :embarrassed:
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Hope you didn't damage the taper on the crank nose.
If the taper is undamaged assemble with a thoroughly dry taper (cleaned with alcohol or brake cleaner).
Use only the proper grade steel bolt (and NO Loctite) tightened to 14 foot pounds and you will have no problems.
Meanwhile rotate your engine using the rear wheel with the transmission in the highest gear. It saves a lot of aggrevation.
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I have never seen this happen! But it was the reason I always used the rear wheel to rotate the engine. Besides being too lazy to take off the cover for the job.
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Man that hurts looking at it!
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Look in McMaster Carr catalog for " tap extractors" for the screw broken off in the crank...
Don't ask, it's a long story...
Can't use just any bolt, go stock, no loctite
Whoops sorry, wrong story...I snapped a tap when I tried to clean the threads on the crank...tap extractor got it out for me
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Up to last year, MG Cycle used to carry a replacement rotor bolt, Bosch original supposedly. I'm not seeing it on their site anymore, so maybe no longer available. The one they sold was "gold" in color, the original Moto Guzzi one is black. Long story short, the new gold one broke while adjusting the valves when turning the engine over with the Allen wrench; I was lucky to get it out by removing the rotor then I was able to grab the broken bolt with pliers. I've also started using the turn-the-wheel-while-in-gear method to turn the engine over now.
Try to find an original bolt if you can, even if used. I think they are class 10.9 in the harness scale (don't quote me), but should be at least 8.8. I personally wouldn't use Loctite in that spot and I would also not use an SS bolt if you can't find the original and have to make one out of something out there.
Good luck.
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Part Number 12 31 8 002 348 (BMW) is a direct interchange for the Moto Guzzi bolt.
Originals were finished in black oxide. Current one on Max BMW site shows a gold irridite finish. Same 10.9 tensile strength.
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Never had one break, but then I never use it to crank the engine over with the spark plugs in. <shrug> Once again, Loops have the superior design... :wink:
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Both plugs out in my case, but I do recall turning the engine a little faster that maybe I should have. I remember making engine revving sounds when I was doing this, and what really did it was when the screeching tire sound kicked-in...that's when the bolt broke. I also stopped doing that when I work on stuff - bad habit :azn:
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I had both plugs out at the time I was rotating the crank with an Alan Key socket.
I have a single plate Ram clutch, not timing marks, I was verifying the TDC D and S marks and then marking the static and advance lines on the RAM.
Bike was hot after along ride, I should have let it cool down before rotating the crank. When cold and with plugs out the crank turns pretty easy.
Harper's have come to my rescue again with the replacement parts I need and the advice I can trust as to removing the end of the broken rotor bolt. :thumb:
Stuff happens,
So long as I can get the remains of the bolt out of the crank without drama it's another lesson learned.
Another tens years or so I may be up to junior apprentice level of a 'real' mechanic. :grin:
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It makes me feel just a little bit better to know that things like this can happen to you too. I was under the illusion that you were perfect - it's good to know that you too are human :boozing:
That you have the courage and openness to admit your occasional mistakes just makes the work you do even more impressive. :thumb: If I were in the market for the perfect bike, I'd be looking your way (or Charlie's).
Nick
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Is the rotor already off the shaft?
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If I were in the market for the perfect bike, I'd be looking your way (or Charlie's).
I've never built a "perfect" bike and doubt I ever will. Do I strive for perfection? Of course, but I've yet to achieve it.
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Perfection is all that's left after the mistakes have been made. As long as there is still a mistake that can happen, you have to drive through it and turn left to find perfection.
Canuck -- bring the busted cover to the national along with the broken bolt. I want to jb weld the bolt in the position you took the pic and install it on the trike. I think that big ol' hole and allen head would look good there, especially since there is no alternator behind it.
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Perfection is all that's left after the mistakes have been made. As long as there is still a mistake that can happen, you have to drive through it and turn left to find perfection.
Canuck -- bring the busted cover to the national along with the broken bolt. I want to jb weld the bolt in the position you took the pic and install it on the trike. I think that big ol' hole and allen head would look good there, especially since there is no alternator behind it.
You got it RK, see you in Oregon.
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Perfection is the enemy of good.
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Is the rotor already off the shaft?
yes, the rotor spun free of the crankshaft as the rotor bolt worked itself loose, when the head of the rotor bolt broke free of the rotor cover ( looked like a chick breaking out an egg!) the bolt caught in the rough edges of the cover, this stopped the bolt from turning and the bolt then snapped, a small section is still in the crank, This all happened in seconds.
The rotor looks fine as does the stator and crank.
I just need to carefully work the snapped off end of the rotor bolt out of the crankshaft.
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I want to jb weld the bolt in the position you took the pic and install it on the trike.
I like it! :evil:
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You got it RK, see you in Oregon.
What are you bringing to Oregon Jim?
I will be on the Mahogany Norge with B.C tags.........
Dale
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What are you bringing to Oregon Jim?
I will be on the Mahogany Norge with B.C tags.........
Dale
I am hoping to bring my Eldorado, the fenders are out getting painted, been gone 5 weeks, I am begging the painter to get them done on time so I can take the cruiser to the rally. Failing that I may be brave enough to take the V7 Sport, just not sure my body can take the Sport for that long of a ride. I could always take a KLR 650 but that seems pretty lame. I will be staying at the America's Best Value Inn, plan on getting in Friday morning. Will look for you at the rally.
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I am hoping to bring my Eldorado, the fenders are out getting painted, been gone 5 weeks, I am begging the painter to get them done on time so I can take the cruiser to the rally. Failing that I may be brave enough to take the V7 Sport, just not sure my body can take the Sport for that long of a ride. I could always take a KLR 650 but that seems pretty lame. I will be staying at the America's Best Value Inn, plan on getting in Friday morning. Will look for you at the rally.
Neeners on you! :weiner: I got mine back from the painter on time, although I think I got old at a faster rate by fretting over it. The trick is to bribe the painter with smoked salmon. Then he gets his assistant to paint it while he goes home and seduces the ol' lady with fish. :rolleyes:
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Perfection is the enemy of good.
Striving for perfection is only good craftsmanship. Demanding it is just being unreasonable. :smiley:
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Jim: Get yourself a set of Snap-on LH drill dits, usually makes short work of such problems. DonG
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Neeners on you! :weiner: I got mine back from the painter on time, although I think I got old at a faster rate by fretting over it. The trick is to bribe the painter with smoked salmon. Then he gets his assistant to paint it while he goes home and seduces the ol' lady with fish. :rolleyes:
I guess that works, if your old lady is a sea lion... :evil:
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Striving for perfection is only good craftsmanship. Demanding it is just being unreasonable. :smiley:
:1: The difference between an OK craftsman and a great one is how they deal with a mistake . In fact that applies to just about any activity . I would tell the young kids working for me in the restaurants , "you will make mistakes , I still do . It is what you learn from them that really matters" .
Of course mine always cost WAAAYYY more money than any mistake made by an 18 year old cook :rolleyes:
Dusty
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I sure hope I never do this again! I have spent over six hours to get the remains of the rotor bolt out of the crank. I was lucky (I guess) that the bolt snapped off at the outer edge of the crank. Unfortunately the spinning of the crank combined with the rotor retained by the outer cover wore the head of the snapped bolt into the outer surfaces of the female threaded recess, in short the stainless steel raw edge of the bolt was practically welded to the crank. No tapping or striking resulted in any ability to thread the bolt out.
(http://i249.photobucket.com/albums/gg217/canuck750/IMG_0580_zpslxqm6u6r.jpg) (http://s249.photobucket.com/user/canuck750/media/IMG_0580_zpslxqm6u6r.jpg.html)
I used a 90 degree air drill and a very sharp titanium drill bit, left hand no less, just a tiny one at first, 1mm diameter, and worked up to a couple mm, Drilling stainless centered through the bolt is a very slow process. Eventually I could get an easy out into the center of the bolt but again no movement at all.
I found a special drill bit that is an 8mm tap / drill and in a hand held tap holder cut through the outer edges until the remains of the bolt broke free.
(http://i249.photobucket.com/albums/gg217/canuck750/IMG_0581_zpsgirzm6gt.jpg) (http://s249.photobucket.com/user/canuck750/media/IMG_0581_zpsgirzm6gt.jpg.html)
I made a thread chaser by cutting some deep cuts into a bolt and then very slowly cleaned the threads. I have a few mm of less than perfect threads but the remainder is all good threads.
Harper's are sending me some NOS rotor bolts, the correct high strength steel type.
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Good save on a tough job.. :thumb: Stainless is no fun to drill by hand.
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How do you spell relief!! Nice save!
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Curtis mailed me a nice used alternator cover, typical wear and tear. I no longer send out my aluminum polishing, It's pretty easy to do, just take time. I have learned a few short cuts, first I use a foam pad palm air sander and a 320 grit sanding disc. I sanded one half of the cover, takes about 5 minutes to get the scrapes and pits out,
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05528_zpshnsreloq.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05528_zpshnsreloq.jpg.html)
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05529_zpst4gufixh.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05529_zpst4gufixh.jpg.html)
Then I use sizol wheel, it has a burlap rope wound into the wheel and cuts very fast,
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05530_zpsziztyb0d.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05530_zpsziztyb0d.jpg.html)
A rouge polishing paste and frequent dressing of the wheel makes the 1st cut quick
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05531_zpstjyx3hoq.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05531_zpstjyx3hoq.jpg.html)
Then the fine wheel and a white paste (white is rougher than red but I want a satin finish)
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05532_zpsi6wzhut1.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05532_zpsi6wzhut1.jpg.html)
and another couple minutes and it finishes like this
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05534_zpsay3vdt6b.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05534_zpsay3vdt6b.jpg.html)
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05535_zpsrg5s7vba.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05535_zpsrg5s7vba.jpg.html)
ten minutes later the other half is done
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05536_zpsbqw91xod.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05536_zpsbqw91xod.jpg.html)
Polishing is messy business but the results are worth it
(http://i249.photobucket.com/albums/gg217/canuck750/1974%20Guzzi%20750S/DSC05537_zpsn9u4dfn0.jpg) (http://s249.photobucket.com/user/canuck750/media/1974%20Guzzi%20750S/DSC05537_zpsn9u4dfn0.jpg.html)
Harbour Freight sells a reasonable priced long shaft bench top polisher and they carry the polishing bricks and various polishing wheels. For under $150 bucks you can get everything you need. My cheap polisher has lasted over five years and done at least 10 Borrani wheels and many other alloy parts.
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Try to find an original bolt if you can, even if used. I think they are class 10.9 in the harness scale (don't quote me), but should be at least 8.8. I personally wouldn't use Loctite in that spot and I would also not use an SS bolt if you can't find the original and have to make one out of something out there.
Good luck.
10.9 would bolt in. I would have thought 8.8 would do as well. SS is not a high strength bolt, stick with high tensile steel. You can get a low grip Loctite that will cause the bolt to resist vibration and not much else if you are worried about it coming undone again.
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Thanks Muzz,
I am going to fit a shnor washer and be done with it!
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Thanks Muzz,
I am going to fit a shnor washer and be done with it!
Wasn't the original washer a "split lock" type?
(http://images1.mcmaster.com/mvA/contents/gfx/large/92147a029p1-b01l.png?ver=1407161974)
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Wasn't the original washer a "split lock" type?
(http://images1.mcmaster.com/mvA/contents/gfx/large/92147a029p1-b01l.png?ver=1407161974)
yeah probably but I trust the shnorr more than the split lock type, originality be damned.
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yeah probably but I trust the shnorr more than the split lock type, originality be damned.
Nice rescue on the crank nose. Why the hell is everyone so convinced these schoon washers or whatever they are called are of any use, same goes for these split spring washers. If you need to use these then its an admission that you are either using an inferior bolt/material (like Stainless Steel, why the heck you would use SS on anything other than a boat I don't know as its a totally useless bolt material) or there is a design issue in the first place. Over 40 years working on aircraft and I've never seen these used in aviation and I've never reinstalled/installed them on motorcycles and engines.
These things are an admission there is an engineering issue, so fix the issue.
Ciao
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The schnorr washer will cope with vibration.
They really do work if you don't want a (usually) nut or bolt to vibrate loose.
Had a case where a farmer who was a customer of ours had a nut on a valve that kept shaking loose. Sold her a schnorr washer and she bet me $20 that it wouldn't work. A month later she came in and handed me $20. (I didn't take it) but I can tell you she was real happy to have found a solution.
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just to be clear....Schnorr/bellevue ... washers are not effective in aluminum they need a hard substraight as in steel to be effective , a wave washer is best in aluminum ....
correct ?
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just to be clear....Schnorr/bellevue ... washers are not effective in aluminum they need a hard substraight as in steel to be effective , a wave washer is best in aluminum ....
correct ?
Ya got me there. :undecided: The "ratchet" action on the washer would be the same; whether the gripping surface on the two faces of the washer need a hard substrate to be effective I don't know. I would have thought that it would still grip on alloy. Must do some research....
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Greg Bender's site has some pictures of Schnoor washers cutting into alloy bearings and rear drive covers, not the best I would think for Aluminum, the old lock tabs seem to work just fine for those applications, but the crank nose and rotor are pretty tough steel.
I had the V7 Sport out the other night for a ride after replacing the rotor bolt and cover, no issues runs like a top, I just love thrashing that 750!
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Good explanation on the use and applications for Belleville washers.
Looks as though aluminium is on the list.
http://ecmweb.com/content/how-use-belleville-washers-correctly