Seized rocker cover allen studs

Just started setting my tappets. Got the rhs off which seems to have been on a while. Unfortunately it seems 3 of the allen studs on the lhs have suffered a failed previous attempt to remove and are rounded, ar$e!!

Any previously tried & tested top tips out there? I’m having a cuppa, avoiding making matters worse!

if you can get to them with a decent but small hacksaw cut a notch into the bolt(s) then apply lots of heat with something like a hot air gun and then tap the bolt around via the notch with a small screwdriver or punch or whatever.if you cannot get a hacksaw in there try a small file, it might take a lot of time. the tank should be taken off to avoid any heat hitting the paintwork, but beware of the then exposed petrol pipe which should be pulled away from the area and covered by something like a old rag and shielded from the heat.if you are not happy re using heat on the bike you dont have to, it might just speed up the job. I can understand one rounded off stud but 3! looks like someone never heard the old saying "if at first you don’t succeed don’t repeat the error twice more"my
old 750 Breva had no rounded off bolts at all on the engine but all
four small cap head bolts holding the front mudguard on were well
rounded off, again I can understand one rounded off bolt but four was
just stupid, do some people never learn?

northwest2013-12-12 12:28:28

I have just had a similar problem on a disc bolt, what I tend to do if this happens is use a Torx key or a multi-spline key of the same size, or a touch larger, than the Allen key, even use an AF if it fits better. These keys have more edges,(teeth) on them than an Allen and will grip a rounded socket better.
Use the shortest one you can find, so it won’t wobble off centre, you may need to tap it into the socket until it grips, then lean into it as you turn it to give it as much purchase as you can, it should give.
As northwest said some heat will help, even just a rag soaked in hot water laid over it or a hot water bottle may be enough to help.

Taking the bike for a run to get it all hot might help too

Plus the old tighten a “TAD” before undoing might get things underway

A dose of PLUS GAS, shock-un-lock, WD40 (YES I dared to say it ) or whatever snake oil you have about can’t hurttris2013-12-12 12:12:16

Had this yrs ago when i first got the V1000, I cut a slot in the head, used WD40 and put brown sauce, very old trick, left it overnight then used an impact driver, they came out as the rocker suds all go thro and are exposed, I always use coppergrease on them…

Cheers all. I’ve set the idle mixtures & done a carb balance and it’s running really sweet now. I’ve blasted them with a bit of WD but I think Ill leave for another day now. (We are moving so I was ‘packing the garage’ today! Went for a run & didn’t sound too tappety so Ill have a proper go when I’ve more time (not rushing!)
Thanks again! :smiley:

2 of mine were seized solid, lots of wd 40 and attacked them with the engine nice and hot after locking a torx bit in to the 2 sized and rounded ones

could only get mine to come loose when i tried with a hot engine guzzi-t52013-12-13 22:08:34

Another possible option, drill the heads off and get new screws (?) Learned how to do this with my Honda CD 175 ~ Honda’s pozidriv engine casing screws are made of licorice but nevertheless are done up to 120 lbs/ft Also caused me to invest in an impact driver, which I still have! When said driver just chews the head out, then must needs resort to the drill… HTH

I had this on 2 of the allen bolts on the sump on a previous Cali.

Space was very limited so I used a dremel to grind the heads off allowing me to drop the sump and get a small pipe wrench on the remaining threaded section.

As GB says make sure you use copper grease when re installing.

+1 for using a Torx bit. I left my caliper bolts with a light spray of “easing oil” for a few weeks and they just wizzed off using the Aldi bargain T-drivers.I didn’t use heat but I think in your case it could be another helper.RegardsJohn

Have used Torx bits in impact driver, have also ground a slight taper on a 1mm oversize allen bit and that works in the driver too.G.

Cheers all. Think Ill put an impact driver on my Xmas list, a chap can never have too many tools!

Don’t use mine that often, but when you need it, you need it

[QUOTE=Mike H]

Don’t use mine that often, but when you need it, you need it   [/QUOTE]

Yep, mines a bit like that as well, but the less said about that the better!!

Also on cap head allen screws on like the rockers a sideways tap will often work as it will compress the corrosion between the bolt and the thread in the hole

Just got hold of an impact driver as well as some stud extractors from a mate so that will be my next little job.

If those are the reverse taper spiral extractors, be very careful using them. They have a habit of breaking off in the stud, so then you have a bit of hardened steel to remove as well.You should not need them anyway. All you need to do is drill down the socket with a 6mm bit, until the head comes off.Then remove all the other bolts either by unscrewing them or drilling in the same way. You can then pull off the cover, and you will be left with about 6mm of stud sticking up from the cylinder head. It is unlikely that they will be tight, but in all events a bit of release fluid, plus a mole wrench will remove them.

When drilling I’ve even had it come loose once the pressure is removed from the head being cut away.

NEVER used those stud extractors I have seen soooo many break in the ‘ole totally stuffing the part… worst scenario is drilling out the old allen head and having to use a nut under the cylinder head, just about all the rocker cover screws go straight thro’ which is why they seize.

Make very sure you get the correct lenght replacement stainless allen head bolts and use good quality copper grease DO NOT overtighten them they only have to hold the cover on and compress the gasket Yet I have seem some people really tighten these bolts down… causing warping and leaks…no need for massive pressure.

Such a shame this thread was not a few days ago warning about extractors…I have just had an extractor snap in the bolt. It looked so easy on the youtube clips I watched…Cobalt drill bits on order to hopefully get through it. The very last rocker bolt snapped in half when I was removing it. Funny (Ha Ha bleedin Ha) thing was, all valves were spot on - didn’t need adjusting.