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Right side exhaust support broken ChC screw.


p6x

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I was going to take a picture of my tail bag and luggage rack and I noticed the missing CHC screw on the exhaust support. (click the link for technical description)

The head just broke. The threaded part of the screw is still in.

To remove what's left of the screw, you drill a hole for an extractor, and hope you are able to get it out. If not, you need to drill the screw out completely, and use an helicoil for the repair.

This is item 42 on the Guzzi spare parts catalog. No specification. Is it M8x125, or M10x150?

_DM36025

Broken Screw exhaust supportBroken screw nomenclature

 

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Is there enough threaded portion of the remaining fastener protruding inboard to get a clamping pliers ("ViceGrip®") on the turn the fastener inboard to remove (after a liberal soaking of penetrating oil-of-choice plus, maybe, a bit of heat gun)?

Sorry for this scary view of my broken frame tab, but it shows how the fasteners can protrude inboard . . .

IMG_0342.jpg

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A more reassuring image. Can you get locking pliers on the inboard protrusion of the broken fastener?

DSCN1081.JPG

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@docc

I can confirm the screws are M8, length 25mm.

I removed the elastic stop nut from behind with a 13mm flat wrench.

Rather than using a vice grip, I am going to try the old trick of using two nuts one against the other. There is also a tool that grips the threads, I forgot the name.

Here's the tool that I would need to use: https://www.grainger.com/category/machining/machine-tool-maintenance/bolt-screw-extractor-tools/bolt-screw-extractors?attrs=For+Bolt+Size|6.00mm&brandName=FACOM&filters=attrs%2CbrandName

_DM36028

 

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Good plan! Better than the drill + screw extractor.

Those fasteners look very rusty, typical for a (Gulf) coastal bike. PBBlaster has worked for me, but maybe not as well as "Ed's Red." (50-50 mix of acetone and automatic transmission fluid).

And heat. Did I mention *heat* . . .  :oldgit:

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Just now, docc said:

Good plan! Better than the drill + screw extractor.

Those fasteners look very rusty, typical for a (Gulf) coastal bike. PBBlaster has worked for me, but maybe not as well as "Ed's Red." (50-50 mix of acetone and automatic transmission fluid).

And heat. Did I mention *heat* . . .  :oldgit:

My tool box is pathetic Docc.... I have nothing but odds and ends.

The proper extraction tool from Facom is expensive. But this is something a guy with a workshop and continuously working on bikes would have.

Already finding Metric size fasteners or anything metric is challenging here. So far, I have purchased all the metric tools and fasteners from McMaster.

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Your idea of using the two-nut method is good. Simply precede the attempt with a penetrating oil and heat application.

Looks like the other fastener should also be addressed . . . 

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1 hour ago, docc said:

Your idea of using the two-nut method is good. Simply precede the attempt with a penetrating oil and heat application.

Looks like the other fastener should also be addressed . . . 

A lot of the fasteners on my bike need treatment. I was hoping it was only cosmetic that I could address after completing the Tour of Texas. It seems that I am going to have to remedy that situation sooner than later.

The head snapping off clean on that screw is a wake up call.

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1 hour ago, p6x said:

A lot of the fasteners on my bike need treatment. I was hoping it was only cosmetic that I could address after completing the Tour of Texas. It seems that I am going to have to remedy that situation sooner than later.

The head snapping off clean on that screw is a wake up call.

Awhile back I placed an order from McMaster for all relevant sized bolts in stainless, mostly socket head and include flat washers and Schnoor in several sizes. Small bags of each. Not a huge amount of money and darned handy to have a little hardware store in stash, having a few metric bikes. I replace everything with stainless where it's low torque or of no consequence.

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Living on the Seacoast myself, I have to admit it's a constant battle to keep the brown menace at bay- 'Rust never sleeps'. 

I replace anything I can with 316 Stainless and what I can't get in stainless I get in a phosphate black and coat it with Cosmoline RP342, either sprayed or applied with Q-Tip. Once dry, you can wipe away any excess you find distracting and it will remain in the pores for the rest of eternity. I haven't seen a spec on anything I've used it on, ever. Shouldn't be a surprise given that was it's purpose from day one, but nobody thinks about Cosmoline except when they have to clean it off a WWII relic.

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10 hours ago, footgoose said:

Awhile back I placed an order from McMaster for all relevant sized bolts in stainless, mostly socket head and include flat washers and Schnoor in several sizes. Small bags of each. Not a huge amount of money and darned handy to have a little hardware store in stash, having a few metric bikes. I replace everything with stainless where it's low torque or of no consequence.

When I purchased my first Japanese motorcycle in the early 70's, they all came with cross head screws. I did not know at that time that Japanese cross heads were different than European ones. We ended up destroying the heads rendering the screws useless.

But dealerships sold socket heads replacement kits for all your motorcycle cross headed screws.

The V11 is equipped with socket head fasteners, but not stainless for the most part.

I wish there were stores like before, where you could go and purchase the exact amount you needed, rather than packs of several.

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2 hours ago, Pressureangle said:

Living on the Seacoast myself, I have to admit it's a constant battle to keep the brown menace at bay- 'Rust never sleeps'. 

I replace anything I can with 316 Stainless and what I can't get in stainless I get in a phosphate black and coat it with Cosmoline RP342, either sprayed or applied with Q-Tip. Once dry, you can wipe away any excess you find distracting and it will remain in the pores for the rest of eternity. I haven't seen a spec on anything I've used it on, ever. Shouldn't be a surprise given that was it's purpose from day one, but nobody thinks about Cosmoline except when they have to clean it off a WWII relic.

Treatments never work as well as proper metallurgy. Black Phosphate or other surface treatments don't work as well as stainless steel.

 

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As anybody ever replaced the Guzzi parts with the appropriate specification for the fasteners?

Like in my original post, the 12/02 spare parts list from Guzzi does not divulge the specification of Item 42.

It would be interesting to have all these Guzzi parts replace by the corresponding specification.

Nobody ever did that?

On the drawing above, the nut is not shown.

Does anyone know what is the latest update Guzzi did of the spare parts catalog? 12/02 is December 2002. Are there any later editions?

I found this on the web; but you can only consult. You cannot download the catalog.

https://www.parts-motoguzzi.com/moto-guzzi-motorcycles/1100-MOTO-GUZZI-MOTORCYCLES/V11/2004/V-11-Le-Mans/FRAME/Lateral-stand--Foot-rests/422/27/332000152/999

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16 minutes ago, p6x said:

 

I wish there were stores like before, where you could go and purchase the exact amount you needed, rather than packs of several.

I've had some good luck at Ace Hardware, they have lots of screws, metric and SAE, different heads.  In fact for the V11 rack, I wanted longer screws than those which came with the original package, and found exactly the same recessed hex head shaped, but a bit longer to get more purchase on the thread at my local ACE hardware.  They were silver, so I just painted the heads black to hide them on the rack frame.  You might have luck finding something similar for these, and they have a long metal frame in the bolts section that you can match your thread to so you can guarantee it's the right coarseness and thickness.

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