Corroded header bolts on 2006 GSXR 750, replace or not?

[Swisscheese]

So I was doing some servicing on the bike and preparing it for winter when I noticed how corroded these header bolts are

As far as I know, the bolts are the original 2006 factory steel ones.

The outermost bolts on both sides don't look too rusty, but the ones towards the center, which are hard to see in the photo, seem almost like the exterior part of the heads have started to flake and crumble away.

I used this bike last winter for some commuting. The anti-rust sprays just seemed to burn off the headers right away, so I suppose there was never protection from road salt.

I'm wondering whether I should attempt to replace the bolts myself now or not.

I need to use the bike for commuting now so really don't want to snap any bolts and be stuck with a non-functioning bike for a while. On the other hand, if I don't replace them now, it seems like they will be even worse for wear after another few months of salt.

I was thinking of trying to soak in WD40 for a day, maybe some heat from a plumbers torch and using a manual impact driver with allen bit, gently tapping it with a hammer (if the allen bit will even grip inside the bolt head without breaking it). If I can get them out, I was going to replace with stainless bolts or maybe titanium ones.

Should I try to replace the bolts now or leave them alone until I don't rely on the bike (I guess it will be out of service if I snap a bolt)? Has anyone else had luck removing very corroded header bolts without breaking them and drilling them out?

[Polarbear]

I wouldn't even go there if you need the bike for commuting. Leave them be until you don't need it for a while (because if you need it it's a guarantee to strip or break the bolts) then clean as well as you can, lots of penetration oil, NOT WD40 and say a few prayers to the motorcycle gods.

Personally if you can get in there with a good 6 sided socket and a manual impact screwdriver I recon that's your best bet. If being the operative word there.
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Triumph Trophy Launch Edition

[jeremyr62]

It depends on if you ever think you will need to remove them for maintenance or exhaust removal. They will be hard to get out now and if they break flush then you will need a friendly welder to get them out. I had similar on a 2004 FJR1300 used in multiple winters and I swapped them out for stainless. They were almost at the point they would cease to act on the clamp. I was lucky and they didn't break off flush, but it was still a job getting them out. Mole grips, heat etc etc.

On my current 2016 GSX-R1000 swapping them was one of the first jobs I did. The bolts were in good nick so came out easily. No help to you I know. I wouldn't bother with Ti. Stainless will be fine.

Back and forth small movements worked for me. I am tempted to suggest an electric impact driver as these are brilliant for getting rusty stuff undone, but you'd have to be careful with the setting so it doesn't just shear the bolt.

[stinkwheel]

As per Polarbear. There's a very high chance of shearing one so wait until you have a time where you can piss on extracting them if they do.

Stainless and titanium are a bad idea, they will gall like hell in that application and heat harden so they'll be both stuck, hard and brittle after a bit and nearly impossible to drill out if they snap. If you're going to replace them, use high tensile steel studs and either long/cap nuts that cover the whole external thread or brass nuts that should round out before they take out the thread. Use ceramic based anti-seize compound on them.

I did this on my VFR750 and used brass acorn nuts which will both protect the threads and strip out readily if I need them too.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[jeremyr62]

[Ayrton]

I'd leave them alone until you need to actually remove them for something. if you snap one then it's a right pain to remove and would probably require you welding something onto it.

If you do try it then heat it up and let it cool completely multiple times and then try and get it off when it's cool. I always thought heating it up just makes it worse and it's going to expand inside the hole and bind harder. You just want to heat cycle it a few times to break the bond.

[WD Forte]

To echo prevous posts.
I'd not touch them until I was kitted up and ready to deal with
every one of the feckers sheering off when removal was attempted.
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bikers smell of wee

[stinkwheel]

[jeremyr62]

My experience of actually doing this would suggest it does not lead to galling or embrittlement and the stainless bolts are easily removed. I had need to do this because my first FJR engine was a ticker and about 4 years after I swapped out the header bolts, I removed them and the headers again to see if I had oil dripping down the valve stems. The stainless bolts came out with no drama whatsoever. I had used a high temperature grease on the threads (a bit like copperslip made by Rocol) at installation.

As I already mentioned, A2 and A4 bolts are austenitic stainless steel. So they are iron alloyed with nickel, chromium and in the case of A4 (316) Molybdenum with a tiny bit of carbon. No amount of thermal cycling will make these embrittle. If you actually have evidence of this happening I would love to see it. These materials get used in far more demanding applications than header bolts. Reactor vessels, boilers, heat exchangers, submarine nuclear reactors, all of which thermally cycle them. The reason they get used is because their mechanical properties are very stable at elevated temperatures.

[stinkwheel]

How did this happen then? Stainless header pipe. Not the first time I've had it happen.

My experience of fitting stainless fittings into alloy casings has lead to the fitting of many helicoils over the years. Titanium is even worse.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Robby]

I don't know about the metallurgy, but I do know the reality.

Stainless studs snap with little warning. Mild steel ones stretch a little first. Then when you have drill them out, mild steel is far easier to drill than stainless.

I'll accept that there may be a type of stainless steel that is ideal for the application, but they aren't using it in any of the stainless studs I have ever bought.

This is one of those areas where I've given up on trying to find a material that works like it should, and I've settled for a workaround that tends to cause less trouble when it does fuck up. Similar to Stinkwheel, that's mild steel studs and brass nuts.

[jeremyr62]

[stinkwheel]

[jeremyr62]

[stinkwheel]

I'll add to my general dislike of stainless fasteners that A2 stainless isn't really very corrosion resistant too. No way you'd get my mudguard bolts off without shearing them, the nuts are just a big blob of corrosion up in there, you wouldn't even be able to get a spanner on them. A4 ones seem to fare a little better.

I personally think BZP ones do better overall. They tend to look rusty after a bit but still retain their shape and usually move once you put some penetrating oil on.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Pete.]

[Polarbear]

[Swisscheese]

Thanks a lot for all the really helpful tips everyone.

I won't touch the bolts at the moment as I can't do without the bike right now.

I'll keep all these tips on hand for when I'm in a position to attack this job that seems like it will be a royal pain in the arse!

[WD Forte]

Whatever the material used on bolts studs, never fit them supertight
just nip them up with lashings and lashings of gnger beer.
(err that should be copperslip! not ginger beer)

I check them from time to time and nip up any loose ones and
if one should fall out, its easier, cheaper and quicker to fit a new
stud or bolt than have to drill/weld a siezed one out.

Guys I knew with k series beemers would often fit new exhaust studs by hand after experiencing the total arseache of removing rotting old studs
which are underneath the engine so not so easy to access in situ.
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bikers smell of wee

[Pete.]

If you want truly seize-proof header studs and nuts. You can even buy copper M8 nuts quite readily as some manufacturers fit them OEM.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[stinkwheel]

If you want to see something truly diabolical, you should see the exhaust studs on Mrs stinkwheels CBR6. They neck down from M8 to M7 as they protrude from the head. There's also no reason for it because the straight M8 ones I swapped them out for fit perfectly well.

I use these which stop the external thread corroding.

https://duax9x73a20d1.cloudfront.net/storage/products/2011/09/08/thumbnails/thumbnail_kvogznd4222t6rnq.jpg
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.