Rounded cam cover bolt - any way to get past this?

[kryptek49]

My 2008 GS500F is on around 20,000 miles so it's well overdue a valve adjustment.

Not using the bike alot currently due to the weather (UK) so figured now was a good time.

I've pulled everything off the bike to get to the cam cover however have run into a bit of an issue.

The final Allen head bolt I need to remove is rusted stiff, and in my attempts to remove it has been rounded off.

It's the most awkward to reach bolt of course.

See attached a couple of photos of the problem: https://imgur.com/a/oxBHzfm

In my mind I have the following options:

1 - Give up, don't adjust valve clearances.
2 - Drop engine, remove bolt with easy access
3 - Try and cut the head off the bolt (No idea how - but if I can do this the valve cover should slide over the top of the rest of the bolt without issue)
4 - Ask you guys for some help!

So does anyone have any ideas on how to solve this?

I have managed to loosen the bolt about 180 degrees, however it's not any looser than it was originally (incredibly tight) and feels rusted to hell.

Thanks everyone.

[Kiwingenuity]

Definately due a valve check..

I had this issue about a week ago when I went to do my valve check on a replacement motor.  Assuming you have tried giving it a dose of penetrating oil, cracking it open a little bit won't help if the thread has some corrosion since lubricant won't get to the thread.

I used some gentle heat then cooled the bolt head with some canned air turned upside down.  What I have found really useful is a hex head that fits my 3/8" socket set - much easier to get in there compared to a regular allen key.  If it's too far stripped you could possibly try getting a larger hex to fit - but is pretty tight to tap it in there.  I ended up getting mine out without dropping the engine out, and swapped the bolt for the rear one.

Plan B for me would have been trying to get some vice grips onto it (but really difficult since the head is nearly flush and domed), or welding a bolt hex head onto it and using a spanner - dropping the motor is a serious hassle..

[max]

If you've already got it to turn 180degree then you've got a decent chance of getting it free.

That front bolt was very rusty when I did my valve check too. You'll probably find that the threads and shoulder are both corroded, hence it getting stuck.

In these cases you need to ease the fastener out, by undoing it a little, spray penetrating oil, then tightening it again, then undoing it a bit more, lube it again, then tightening again etc. etc. As mentioned, a little heating would help too.

Due to the lack of space I'd say your best bet is to chase the bolt around using a hammer and cold chisel using the technique I gave above (be careful not to slip and smack it into the rocker cover).

Good luck!

[kryptek49]

Thanks guys,

The bolt is 100% rounded so no use trying to use a torx bit/bigger socket.

Thanks for the idea max - I'll buy some chisels tonight and have a go.

Really don't want to drop the engine as I know the main engine frame bolt is a bloody night mare to remove - had a quick go at mine and I can see the bolt head turning on one end and the nut doesn't move on the other - bit worrying!

[kryptek49]

Well my attempts with a chisel didn't go down well.  All it's done is cut off half of the side of the bolt.  I could probably chisel the entire bolt away and it wouldn't budge unfortunately.

So if chisels won't work does anyone else have an idea?

Thanks

[grader]

any chance of cutting a slot in it and using a large flat screwdriver on it?

[kryptek49]

No not at all unfortunately, there's no straight down view at the bolt so I'd have to angle the screwdriver meaning it would be more likely to slip.

Also I am 100% sure based on how the bolt has moved so far that I couldn't turn it with a screwdriver.

Also no clearance to cut the slot unfortunately

[Kilted1]

Is there enough of the head left and access to drill a hole and insert a rod to turn the bolt? 

There's lots of YouTubes on how to deal with a broken or stripped bolt, but getting to it seems to be the main issue.  It seems you may be stuck dropping the engine or at least taking enough apart to move it around some.

Another reason to keep up on maintenance so things like this can be dealt with before they become a major problem.

Sympathies and good luck!

[max]

<Snip>

Really don't want to drop the engine as I know the main engine frame bolt is a bloody night mare to remove - had a quick go at mine and I can see the bolt head turning on one end and the nut doesn't move on the other - bit worrying!

If the whole thing is turning then that can actually be a good sign as it shows the shaft isn't seized in place, which is usually a bigger hassle than a rusted head/nut.

Shame about the bolt head breaking, did it just crumble when you chiselled it or at least get some more movement? Can you show us pictures of what's left of it too?

It's sounding like engine out at this point due to the lack of access...

[Kiwingenuity]

Out of interest, what's the access like if you drop the oil cooler out of the way? would that ease access issues?

[kryptek49]

Is there enough of the head left and access to drill a hole and insert a rod to turn the bolt?

Thanks for the help, unfortunately there is no top down access meaning I would not be able to drill straight into the bolt.  I've looked at various bolt removal techniques but none seem to cover bolts like this where this only 2 inches of clearance at most.

If the whole thing is turning then that can actually be a good sign as it shows the shaft isn't seized in place, which is usually a bigger hassle than a rusted head/nut.

Shame about the bolt head breaking, did it just crumble when you chiselled it or at least get some more movement? Can you show us pictures of what's left of it too?

It's sounding like engine out at this point due to the lack of access...

The bolt never loosened up when I initially turned it though, potentially I was just twisting the top of the bolt and the bottom is rusted in place completely.

I'll add a photo of the bolt when I'm back from work later today.

Out of interest, what's the access like if you drop the oil cooler out of the way? would that ease access issues?

I could remove the oil cooler, however the access gained is severely limited by the front wheel & forks. 

I'm thinking I could possibly buy a multi tool like this: https://www.clasohlson.com/uk/Cocraft-HMT300-Multi-Tool/18-3619?gclid=EAIaIQobChMIk5GVwt3i3wIVq5ztCh0tRwIYEAQYAyABEgJMWvD_BwE and see if I have enough clearance to chop the head off the bolt, thoughts?

Thanks all for the help

[The Buddha]

Well my attempts with a chisel didn't go down well.  All it's done is cut off half of the side of the bolt.  I could probably chisel the entire bolt away and it wouldn't budge unfortunately.

So if chisels won't work does anyone else have an idea?

Thanks

If you chiseled the top off you should be able to get the valve cover off, then you'd have enough to grip it with a pair of locking pliers.
I think that's your best bet.
Cool.
Buddha.

[kryptek49]

I've only removed a small portion of the top of the bolt so far, however that may be the answer if it still doesn't move

[max]

Re the engine frame bolt, my bad I misread your post as the nut was also turning. Yeah that's definitely a worry.

I've usually found it good practice to loosen/tighten the nut rather than the head of the bolt, e.g. on axles. Just personal experience and not particularly relevant, but fyi.


+1 for Buddha's recommendation too.

[Kiwingenuity]

the multi-tools like that are generally not suited to cutting hardened steel - or anything metal aside from the thinest sheet metal / nails etc.

I would look towards Buddah's idea of getting the head off - a small die grinder (like a Dremel) might be a lot easier to wrangle in such a tight spot.  If you worked on the top centre of the bolt and ground out it should minimise the risk of damage to the valve cove,  then a pair of vice grips to deal with the stump.

[Numewsm]

Same size Allen key or hex and add a dab of valve grinding paste to the end of it.  It'll give you the extra grip you need to remove the bolt.
Mine was the same issue with the same bolt but I managed to get it out this way. 🥳

[Kiwingenuity]

Now thats a neat trick - squirrelled away that Acorn for future use..

[kryptek49]

Update time - managed to remove the head of the bolt without to much damage to the cam cover.

Lifted the cam cover over the shaft of the bolt and used some vice grips to twist what was left out.

I'll let this picture speak for itself:

https://imgur.com/a/zJOQjky

So as you can see I've left about 80% of the thread in place as the bolt sheared.  Due to the location of the bolt there is 100% no chance of drilling it out and re tapping it.

I see two options - please can you let me know which you think is best?

1 - Drop engine, drill and replace bolt.
2 - Cut new bolt down so only a few threads remain, thread it into the existing hole on top of the existing bolt threads.

Now no. 2 is clearly the easiest, but is there any reason not to do it that way?

Thanks for all the help so far

[sledge]

Drop the engine

Why?

Just pull the head off.

And unless you have experience with drilling out and reclaiming broken fastenings/threads and the correct kit to do the job find someone competent to do it. This is not one to be practising on. The head is much softer than the remnant, screw it up and you will be in a world of pain.

[kryptek49]

Can you pull the head off without dropping the engine? I assumed there wasn't enough clearance, however I have no idea what I'm doing past this point