Sheared valve cover bolt... Shit.

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

I knew it was going too well! Over the last couple of weeks I've been stripping down parts of my bike and giving it a well-deserved service/clean. Today was the last job (apart from putting on the new radiator when it arrives), valve clearances. All done and close enough, putting the valve cover back on and the ratchet slips.

Shit. Oh... Please don't tell me... FUUUUUUCCKKK!

Thought I'd cross-threaded it for a bit and then the true gravity of the situation struck me...

Now the screw part of the bolt is probably 1.5cm long, and all but 2/3mm of it is stuck in the top of the engine casing, about 2/3mm (surprisingly) underneath the level. So I can't get anything on it to screw it out, also the frame is directly above it so screwing straight down into it with a screw extractor or similar is going to be very difficult, not sure if the screw is even a large enough diameter for this to work effectively?

Thought about hammering a screwdriver in to make a groove and then unscrewing it but quickly dismissed that idea as being very very difficult, if it was even possible. What the fuck can I do? I'm so stressed right now.

I assume I'd be very stupid (even more so than I already feel for shearing it) to ride it with just 3 bolts in there.

So I put it to you BCF, any bright ideas? (Please?) Do I just wait til the rad gets here then screw it on as tight as possible and ride to the garage for them to deal with? (Probably negating any cost saved servicing the bike myself).

Sorry for the lack of pictures, I don't actually own a camera and even my phone doesn't have one!

gmanxiii · World Chat Champion Joined: 20 Nov 2006 Karma :

ive sheared off two valve cover bolts in the past and managed to get them out with a tiny flat screwdriver. Because theres no head to keep the thread tight it should be fairly easy to just pick out. Theres normally a little lip on the back that you can catch with the screwdriver. Just catch that with the screwdriver or something long and sharp and you can rotate it out.
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VFR400NC30 > ZZR600 > CBR600FX > CBR1000rr

gmanxiii · World Chat Champion Joined: 20 Nov 2006 Karma :

heres a small diagram to make more sense
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VFR400NC30 > ZZR600 > CBR600FX > CBR1000rr

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

WHat bike is it? Is the frame tube fully above the hole or could you perhaps get past it with a very long drill bit (or a bit with an extension).
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132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

I see what you mean! I've just had a go and unfortunately I think the screw is too deep/small diameter for this to work Sad

yen_powell · World Chat Champion Joined: 22 Jun 2008 Karma :

I've had the same thing happen to me. As said it's probably not even tight any more.
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Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Having a second look, if I had a very long drill bit, I might be able to get through between 2 pieces of the frame, but it would be close. It would have to be probably 20cm long, and then it would be 2/3mm thick so very fragile and I wouldn't trust myself to drill straight with a bit that long!

It's a 1994 CB500

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

No room for an angle-head drill?
____________________
a.k.a 'Geri'

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

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

About a 15cm gap between the frame and the hole when the valve cover is off, probably not enough room even for an angle headed drill when a bit is added

Frost · World Chat Champion Joined: 26 May 2004 Karma :

If this is just the valve cover, can't you just undo all the other bolts, remove the cover then just undo it with some pliers? As said above, the bolt needs a head on it to keep it in, the head being squashed against something it what causes the thread to bite in. Once the head is gone you can undo a decent condition bolt with just your fingers on the thread.

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Once the cover is off the bolt is still hidden about 3mm inside the hole in the lower piece! Sorry if that doesn't make sense...

Ichy · World Chat Champion Joined: 15 Jul 2005 Karma :

Very similar to Gmanxiii but rather than a screwdriver I would try a Pick and just coax it around.

https://www.king-tool.com/img/tools/tool-groups/480/hook-pick-sets.jpg

Its surprising how well they work some times.

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

I've spent quite a while now poking and picking at it with a variety of small screwdrivers. I've also carefully sprayed some WD40 down into the hole in the hope it would seep down the sides of the thread. There is absolutely no sign that the screw is going to budge at all.

I'm starting to realise the only way this bastard is coming out is by me dropping the engine and drilling it out properly...

I really don't fancy doing that especially as I've already spent about 2 months off the road Evil or Very Mad

So as soon as my new radiator arrives I think I will put it all back together with a new gasket and just use some bathroom sealant to hold the top of the 4th bolt in. With any luck there won't be any leaks as 3 bolts will be enough to hold it down. Is this a stupid idea?

If that doesn't work out I guess I'm going to have to drop the lump and go at it properly!

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Ok so now a new problem, started the bike up and got white smoke coming from the exhaust manifolds, didn't replace the gaskets when I took the exhaust off as there were none, but it didn't smoke from here before! Any ideas?

Frost · World Chat Champion Joined: 26 May 2004 Karma :

It might just be oil or something burning off. Check around with your hand and make sure there is actual pressure behind it. If there is, you probably put the pipes in at an angle and they've not gone in far enough.

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Just phoned up the garage and they said either the head gasket is gone causing water to get into the engine from the radiator which means smoke comes out. I don't see why it would have just gone though when I haven't ridden the bike in weeks.

He also said the bolt being sheared might cause water to be able to get into the cylinder which could cause the smoke but again I don't really see how any water would get in there.

The smoke is definitely floating out rather than being pumped out by the engine, I think the exhausts were seated properly but I guess they can't be if anything at all is getting out?

Is it common for aftermarket exhausts not to have manifold gaskets?

gmanxiii · World Chat Champion Joined: 20 Nov 2006 Karma :

no you'll need gaskets. If they are the circular pipe types that get crushed when you fit the pipes, i think theres a possibility that when you took the pipes off you couldnt see the gaskets as they end up really flat and the edges tend to be surrounded by muck on the outer edge and black exhaust dust on the inner edge. Its something ive done before myself, but a bit of poking with a flat bladed screwdriver should have revealed them. The smoke coming out its likely to just be exhaust, when you refitted the pipes its probably not sealed properly.
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VFR400NC30 > ZZR600 > CBR600FX > CBR1000rr

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Went out today and found the gaskets! Have ordered some new ones. Once they're fitted the smoke should stop I assume. If so do I stop worrying about the head gasket being fucked or is that still a possibility? Also still wondering about riding without the one valve cover bolt...

If the smoke continues to come out, but from the end of the exhaust pipe I suppose that means the head gasket may indeed have blown?

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

If I were you, I would have someone you trust take a look at your bike, before taking the word of the garage as gospel. I think what they have told you is very unlikely.
____________________
a.k.a 'Geri'

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

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

I did think that, I don't think the guy quite understood what I was telling him and wondered why the gasket would have blown without me even riding the bike! I think I will fit the new gaskets, see if it's still smoking and then ride down to the garage (I only spoke on the phone to one of the car guys before) as there isn't anyone I know really with this sort of knowledge about bikes! It seems to me that there's enough tension from the 3 valve cover bolts to keep the cover on tightly, but I don't know if there's any force from the engine which might mean all 4 were needed?

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

I've never seen a valve cover with a stripped/broken bolt that didn't leak oil, remember the insides are slightly pressurised. You are better-off getting it repaired.
____________________
a.k.a 'Geri'

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

loply · World Chat Champion Joined: 24 Mar 2004 Karma :

I'm not sure if I followed this thread right but...

If you have a broken bolt securing the head (or rather, not securing it) then clearly the gasket might not been under pressure, potentially right where a waterway or oilway is?

As such I guess it'd make sense if it's leaking and/or if coolant is mixing with oil.
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Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

I think that's what the guy at the garage understood from what I told him, but in fact it's only the bolt holding the valve cover on which I've sheared, as far as I'm aware this has no relevance to the head, which is why I wondered what it has to do with the head gasket!

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Ok just a little update, spoke to the garage again this morning and Jim the bike guy was there. He said I'd be able to tell if the head gasket was gone as I'd be able to hear the air being pushed out. He also said if the valve cover wasn't leaking (doesn't seem to be but I will test that later) then he wouldn't bother fixing it.

Checked in my Haynes manual and the head can be removed without taking the engine out, so I'd be able to sort the head gasket and drill the bolt out and then put it back together. The garage said this would cost about £200, but obviously if I trusted myself I could take it apart myself and just take it in for the drilling.

Will put the new manifold gaskets on when I get them and see if this stops the smoke, then I'll try spraying fairy liquid with water around the engine to see if there are bubbles when it is cranked over (Jim suggested this to test for blown head gasket).

After all that I'll take it for a ride to see if there's an oil leak!

So thanks for you help everyone, Very Happy

will report back again after new manifold gaskets fitted