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Discussion Starter · #1 ·
Hi everyone,

I was about to replace the exhaust on my F4 750 and I found out that the head on one of the bolts is rounded/stripped (sorry, I am not sure what's the right expression for this). Picture below.

The one from the other exhaust tip came out without problems but this one I am unable to unscrew it, and I am afraid I might have made the problem even worse as I gave it a couple of goes.

Is there anything I can do? The bike is due for servicing next week, should I just leave this for a professional and ask for that bolt to be replaced? I hope this is not too bad :unsure: I think I could have worked something out myself to extract it if it wasn't for the location of the screw, it is quite difficult to access.

Thanks in advance,


485822
 

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What type of socket were you using? That bolt can stay in place and you can remove #11...the one you see in your picture that is directly above but not circled. Then you can work on removing the damaged bolt.

485823
 

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Hi try gently tapping / pushing a Torque bit into what's left of the head.
You maybe lucky and find a Torque bit will grip better than a hex key.
 

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Hi everyone,

I was about to replace the exhaust on my F4 750 and I found out that the head on one of the bolts is rounded/stripped (sorry, I am not sure what's the right expression for this). Picture below.

The one from the other exhaust tip came out without problems but this one I am unable to unscrew it, and I am afraid I might have made the problem even worse as I gave it a couple of goes.

Is there anything I can do? The bike is due for servicing next week, should I just leave this for a professional and ask for that bolt to be replaced? I hope this is not too bad :unsure: I think I could have worked something out myself to extract it if it wasn't for the location of the screw, it is quite difficult to access.

Thanks in advance,


View attachment 485822
You'll have to replace it but you can use a Dremmel or other small rotary tool with a cutting wheel to cut a slot in the bolt so you could use a flat-head screwdriver to extract it.
 

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Also try some penetrant and heat before attempting to undo it as described above just to be safe. It is likely some munter has rounded it out because the hole on the plastic cowl above the exhaust didnt line up with the exhaust hole or It may be rounded out because it is seized.
If this is the case it may even be cross threaded, so check that when you do get it out. I had to retap a cross thread on my RG3s when I bought them. Not a biggy, but would have been nice to know 😀.
The next step is loctite freeze and release (it works wonders) and a left hand drill bit to drill out the centre large enough for an easy out.
Patience is the key. If you snap the head off relax all is not lost:
This video is excellent for those where the head gets broken off

I quite like the hinge bolt or drilled put allen method to protect threads.

I would suggest undoing the bolt for the top of that bracket so you can remove the muffler and work on it off the bike.

One last tip....GO SLOW. If you find yourself getting annoyed walk away and come back later...its cheaper that way 😁

Lettuce know how you go.
 

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Discussion Starter · #6 ·
What type of socket were you using? That bolt can stay in place and you can remove #11...the one you see in your picture that is directly above but not circled. Then you can work on removing the damaged bolt.

View attachment 485823
Thanks for the suggestion and the diagram, definitely will do this. I will remove 11 and then get the whole exhaust out. With the exhaust out should be easier to get the bolt out. I was using one of the Allen keys from the toolkit (pic below), attached to a T wrench that I have. Perhaps this wasn't a good idea.


485831



You'll have to replace it but you can use a Dremmel or other small rotary tool with a cutting wheel to cut a slot in the bolt so you could use a flat-head screwdriver to extract it.
Thanks for the suggestion. Will definitely replace it after I manage to extract it. I will do a bit or research to find out what's the bet replacement for it in terms of size and length.


Also try some penetrant and heat before attempting to undo it as described above just to be safe. It is likely some munter has rounded it out because the hole on the plastic cowl above the exhaust didnt line up with the exhaust hole or It may be rounded out because it is seized.
If this is the case it may even be cross threaded, so check that when you do get it out. I had to retap a cross thread on my RG3s when I bought them. Not a biggy, but would have been nice to know 😀.
The next step is loctite freeze and release (it works wonders) and a left hand drill bit to drill out the centre large enough for an easy out.
Patience is the key. If you snap the head off relax all is not lost:
This video is excellent for those where the head gets broken off

I quite like the hinge bolt or drilled put allen method to protect threads.

I would suggest undoing the bolt for the top of that bracket so you can remove the muffler and work on it off the bike.

One last tip....GO SLOW. If you find yourself getting annoyed walk away and come back later...its cheaper that way 😁

Lettuce know how you go.

Thanks Glenno! It is great to know that is not all lost! I did get a bit stressed at the moment and those couple of attempts to get it out came out of frustration. I knew it wasn't a good idea because I made it worse.

I actually just watched a video from the same channel. Once I get the exhaust out I will first clean the head properly and apply some heat, then just slowly tap it from the side with a hammer. Fingers crossed nothing else will be necessary to extract it.

I will let you know what happens. Cheers everyone for the advice (y)
 

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Drill the head off, then you can unscrew the shank with pliers. You have to replace it anyway.
 
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Drill the head off, then you can unscrew the shank with pliers. You have to replace it anyway.
I was thinking that, but he might want to wait until he know of that fastener is galvanically corroded into the threads. Having the head to grip with, say locking pliers, might give him the torque needed to break it free, Use of a penetrating oil is recommended.
 
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Discussion Starter · #9 ·
Some quick update.

Following silentservice703's post I removed screw #11 without any problems, so that's some progress as now I know I can remove the pipe. I just need to get a tool to pull the springs out and release it.

I hoped I could do it by hand or just pulling with the screwdriver but I it wasn't that simple. I am going to have some patience and do things with the right tools before I break something else!

Will keep you posted on the progress (y)
 

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To remove springs get some heavy gauge wire or some safety wire and loop a long piece over each spring hook one at a time. Tie the wire around something you can use for leverage and pull
 

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I have had good success with a pair of long nose pliers side ways when away from home.
 

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Discussion Starter · #13 ·
Hi everyone,

Well there has been some progress, but I am afraid there are good news and bad news.

The good news first. I managed to unscrew the bolt in question. I simply gently tapped counter-clockwise the metal piece that holds the exhaust to the subframe and the screw became lose to the point I could just rotate it with my fingers:

485972


Voilà:

485973



The bad news. There is another problematic bolt, rounded head too. Trust me I have tried everything and this f****r won't come out, even after cleaning it and applying some heat:

485974


I have even rotated twice 360 degrees that metal piece smashing it with the hammer. It is slightly loose and you can pull it with your hands. However the bolt is completely stuck, it is not moving.

Going to take a break and might carry on later.

Cheers everyone for your advice.
 

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Penetrating oil soak (Kroil) and then try TIGHTENING slightly before loosening. If still stuck use a MAP torch and get that bolt head RED hot, let it cool a little, re-apply Kroil, let it soak. Repeat tighten then loosen.
Good luck. and patience.
 
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Kroik is magic, or you can use The KNURL’s concoction of acetone and ATF.
As for the heat cycle, remember that heat expands metals and the purpose in this case is to compress the particles of corrosion that have the threads locked in place.
So, soak in pens tearing oil, go tighten to crush and release, and then loosen.
Think of it like using a tap to thread the hole.
That is a very soft bolt and it will snap easily.
Use a pair of locking pliers to grip the head.
 

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Heat it then apply LOCTITE FREEZE AND RELEASE. My mate recommended it when he used it on some old machinery on his farm. It worked a treat on some old header studs off a bike I purchased from the coast.
Also consider an impact driver like the one pictured
485977
 

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Hi everyone,

Well there has been some progress, but I am afraid there are good news and bad news.

The good news first. I managed to unscrew the bolt in question. I simply gently tapped counter-clockwise the metal piece that holds the exhaust to the subframe and the screw became lose to the point I could just rotate it with my fingers:

View attachment 485972

Voilà:

View attachment 485973


The bad news. There is another problematic bolt, rounded head too. Trust me I have tried everything and this f****r won't come out, even after cleaning it and applying some heat:

View attachment 485974

I have even rotated twice 360 degrees that metal piece smashing it with the hammer. It is slightly loose and you can pull it with your hands. However the bolt is completely stuck, it is not moving.

Going to take a break and might carry on later.

Cheers everyone for your advice.
Have you tried vise grip pliers?
 

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Registered
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Hi everyone,

Well there has been some progress, but I am afraid there are good news and bad news.

The good news first. I managed to unscrew the bolt in question. I simply gently tapped counter-clockwise the metal piece that holds the exhaust to the subframe and the screw became lose to the point I could just rotate it with my fingers:

View attachment 485972

Voilà:

View attachment 485973


The bad news. There is another problematic bolt, rounded head too. Trust me I have tried everything and this f****r won't come out, even after cleaning it and applying some heat:

View attachment 485974

I have even rotated twice 360 degrees that metal piece smashing it with the hammer. It is slightly loose and you can pull it with your hands. However the bolt is completely stuck, it is not moving.

Going to take a break and might carry on later.

Cheers everyone for your advice.
smack a tighter fitting allen key in it, then get yourself a thin flat blade screw driver, lever it between the tab and pipe and unscrew the bolt while lifting or pushing down on the flat blade to force it up while you unscrew it at the same time,
 

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Discussion Starter · #20 ·
Hi everyone,

After trying everything (heat, MD40, a bigger Allen key, Vise-grip pliers...) without success, I finally sanded the head completely. Well, not completely, until it broke (picture below). Took a bit of effort but I managed to do it. I know it is a bit of an overkill approach but I was only interested in the bracket. I will probably trash the exhaust as I have a new set of RG3s I am planning on fitting.


486076



On another note, I ordered a couple of new bolts to attach the bracket under the new exhaust. It turns out, and assuming the part number is correct, the bolt it was used on my bike is longer than what it should.

Picture below. On the left the bolt I managed to extract, on the right the pair of new ones I bought. Maybe whoever installed the exhaust picked a longer bolt and forced its way in? It would explain why it was impossible to unscrew!


486077


Anyway mission accomplished, thanks everyone for all your suggestions! :)
 
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