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Cylinder head thread repair?


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Sorry for another post, but I'm all in on getting to know my new V11.

 

Well, all was going smoothly this afternoon.... My new MG Cycles shop stand arrived along with fresh valve cover gaskets and new spark plugs. Covers removed, valves inspected - hey they were perfect! New spark plugs gapped and reassembly in progress. Well two of the threads on the right cylinder head got cross-threaded (indicated in the photo). Now I'm super meticulous, starting them by hand and crisscrossing my way around the cover with a torque wrench at 10 NM. Anyhow. Two of the damn threads got cross-threaded. Not sure if they were already buggered or it was me. Anyhow, simple helicoil fix?

 

Ran great, no leaks but I'm a little OCD and want all bolts properly seated.

 

I've done valve adjustments on my Griso's, and V7 with no drama but dang these heads seemed soft!98fe1279f015d77c6c5449cef219f162.jpg

 

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8 minutes ago, daviscr5 said:

 

Sorry for another post, but I'm all in on getting to know my new V11.

 

Well, all was going smoothly this afternoon.... My new MG Cycles shop stand arrived along with fresh valve cover gaskets and new spark plugs. Covers removed, valves inspected - hey they were perfect! New spark plugs gapped and reassembly in progress. Well two of the threads on the right cylinder head got cross-threaded (indicated in the photo). Now I'm super meticulous, starting them by hand and crisscrossing my way around the cover with a torque wrench at 10 NM. Anyhow. Two of the damn threads got cross-threaded. Not sure if they were already buggered or it was me. Anyhow, simple helicoil fix?

 

Ran great, no leaks but I'm a little OCD and want all bolts properly seated.

 

I've done valve adjustments on my Griso's, and V7 with no drama but dang these heads seemed soft!98fe1279f015d77c6c5449cef219f162.jpg

 

Sent from my SM-G960U using Tapatalk

 

 

 

Yes or my preference a Timesert repair.

Ciao

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Yes or my preference a Timesert repair.
Ciao
Thanks, I had not actually heard of a Timesert until now. Looks like a good fix

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Have you tried just chasing them through with a taper tap?
No Sir, is that something I can pick up at Ace?

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I'd imagine so. It's a 6x1.25 thread I believe, using a taper tap, at least at first, will allow you to chase the good threads lower down and the the parallel part of the tap will chase the buggered bits. Finish it off with a bottoming tap. If it's only the upper couple of threads that are mullahed it'll probably come good.

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Is that an aftermarket head guard? looks like it. It appears countersunk at the bolt heads but if it's thicker than stock guard then the bolt will come up short of some threads, if using stock bolts. Even if that isn't a problem I wonder if there is enough depth in those holes to maybe get a bit longer bolt in. A couple extra threads couldn't hurt.

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Timesert is a plug , and Helicoil is a spiral thread kit and looks like a spring . Are you sure the screws are not too long ? 

 There is nothing soft about the cylinder head threads . People install the wrong length screws and trouble happens or try to torque these screws to 25 ft.lbs. . Please treat these like Phillips head screws when you tighten them .

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Thanks Pete, footgoose and gstallons. Yes, I believe the head sliders are aftermarket. The bolts appear to be the correct length but are a bit shinier than the originals. I was really careful screwing them back in so I suspect they must have already been buggered. The Timesert looks like a good repair but ill try to clean the threads first. Thanks again-

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I bought a Timesert thread repair kit for 5.4 Ford trucks that blow out spark plugs . $$$$$  It is a bulletproof kit . GM approves Timesert for Cadillac ( the worst junk rolling ) head bolt repairs .  

Fastenal sells a repair kit too . The 6mm kit is a plug that uses a 1/4 20 tap to install .  

BTW , I am the king of twisting off , stripping / crossing / boogering up threads . 

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I bought a Timesert thread repair kit for 5.4 Ford trucks that blow out spark plugs . $$$$$  It is a bulletproof kit . GM approves Timesert for Cadillac ( the worst junk rolling ) head bolt repairs .  
Fastenal sells a repair kit too . The 6mm kit is a plug that uses a 1/4 20 tap to install .  
BTW , I am the king of twisting off , stripping / crossing / boogering up threads . 
This is helpful info. There's never a dull moment with these wonderful Guzzis. Thanks for the tips!

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same issue i inherited on my red V11.  and i've seen it on other bikes, including other makes, including some "bavarian" machines.   at this point on my v11 just being gentle with those bolts is fine, as its not a high stress area.  and i agree that bolt length is a real factor.... first time i tore into my new-to-me Red machine, there was significant mix-and-match in the bolts/screws i was pulling out.   perhaps this winter when the prime riding season is behind us i'll dig back into those again as well, and consider doing some better fixes.  but starting with a parts diagram that confirms which length bolt for which hole would be a good box to check.

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And why not Valpolini head cover gaskets, the best for the best.
Cheers Tom ea5074b84fdf826c439d0dbc4a13d1cb.jpg

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3 hours ago, Gmc28 said:

same issue i inherited on my red V11.  and i've seen it on other bikes, including other makes, including some "bavarian" machines.   at this point on my v11 just being gentle with those bolts is fine, as its not a high stress area.  and i agree that bolt length is a real factor.... first time i tore into my new-to-me Red machine, there was significant mix-and-match in the bolts/screws i was pulling out.   perhaps this winter when the prime riding season is behind us i'll dig back into those again as well, and consider doing some better fixes.  but starting with a parts diagram that confirms which length bolt for which hole would be a good box to check.

Forget the parts book,pull the cover and thread a bolt into the hole until it bottoms out or is flush with the end of the open threads and then measure the distace from the sealing surface to the underside of the fastener then the thickness of the cover and gasket and subtract 1mm and use that length. On the open holes you can obviously be a little longer but not too much as you dont want dirty/corroded threads running through the threads on the way out.

Ciao 

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2 hours ago, Lucky Phil said:

Forget the parts book,pull the cover and thread a bolt into the hole until it bottoms out or is flush with the end of the open threads and then measure the distace from the sealing surface to the underside of the fastener then the thickness of the cover and gasket and subtract 1mm and use that length. On the open holes you can obviously be a little longer but not too much as you dont want dirty/corroded threads running through the threads on the way out.

Ciao 

That would certainly  be best.  I just offered the low lying fruit.... and like to know if there’s something else amiss if the Italians think one size should fit but then it doesn’t match what i find, so then i pause.  I found a sheered bolt at one point, but it was a (fairly) clean sheer, so took me an extra minute of head scratching when reassembling from the batch of bolts in the parts tray as to what was going on. 

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