Hitchcocks Forum

Got a spare minute yesterday and took the head off the bullet, had already removed the axhaust and carb, everything went simply until lifting the head from the barrel, it seems at some point someone has refitted the head with setting silicone gasket sealant and it was well and truly stuck fast.
Even after some serious welly with a hefty rubber mallet all around the head it was refusing to budge the tiniest bit. I'm always very wary around cylinder head mating surfaces and even levering with a 'pry bar' (hefty screwdriver), between the barrel and head fins it didn't yield at all.
To finally get it to let go of it's silicone grip, (this may prove useful to others), I took a slightly tapered 'drift' (yep, another hefty screwdriver) and walloped it in bit by bit on the front and rear fins between the head and barrel, the slight taper helping to lift the head a loosen the seal and this way the only real risk was snapping a couple of fins, as it happens it freed off and with a good bit of wiggling it came loose.
Now for the helicoiling, clean and decoke, (the head and piston crown other than some sooty carbon deposits look good), i'm going to lap the decompressor and valves back in to make certain they're sealing as I seemed to have lost compression just after the plug threads stripped, (even with the plug out and a thumb over the plughole), currently I don't know if it was the decomp or a valve wedged slightly open, hopefully that and not the piston rings.
I have a new gasket set with a copper head gasket, need to get some Blue Hylomar but I was wondering, has anyone fitted a copper gasket without, is the Hylomar really necessary?

Cheers,

Mike

Hello matey !!-----------Damm-my you're a lucky one and no mistake. From your description my guess is that head's not been off since leaving the factory----I had the same trouble with my 2005 Classic 500 with 6,000 miles on the clock during last winter. And that was a known "first timer". It was almost like cement and, like you, I had to employ methods "not taught as an Apprentice"---but it got the job done right up to the very last levering when the top fin went "PING!!!". Ah well---good job I know a decent cast-iron welder. Incidentally there was a thread on here a while ago where someone posted a bolt-on lifting bracket design.Looked quite effective too. At this stage might I suggest you consider our hosts oversized exhaust valve ? Perhaps a valve stem seal on the inlet guide and give the inlet tract a bit of a clean-up??>>>>>>Now then-- what's your bikes mileage ?? Do you feel up to a cylinder removal to give the piston a good inspection and---if the bore etc is OK then a fresh set of rings would not go amiss.( If you do, don't forget the base gasket. I usually rub grease into these and the rocker cover ones to aid dismantling the next time.).Finally the head gasket and }----TO seal, or NOT to seal, that is the question? Personally with these bikes at this poor quality level I use the composite gasket (the American-made one our hosts sell. It is applied DRY and has a good "Fire ring" built in). Mine's running very well. If you do want to use the copper one then---a) It will need to be annealed before use--even though it's new. and --b) dry and loose-assemble the head onto the barrel. Measure the gap between them----it must be SMALLER than the thickness of the copper or there will not be sufficient compression of the head onto the gasket. Use WELLSEAL on all mating faces. Put a ring of it around the outside of the two pushrod tunnel holes and one around the bore hole. It will "squish" out when tightening the cyl. head nuts. Allow it 5 to 10 mins before assembling. Torque-up in sequence and to the stage values given. Don't forget to re-torque at the appropriate time. I've the same to do on my No2 bike this Bank Hols plus 2 gearbox sprockets--------ah, there's a thought. Have you fitted an uprated sprocket ?? It's really worth the effort. And now---what to do AFTER Breakfast, eh ????

I rather doubt that it was just sealant holding the head.
One of the things that makes Bullet heads difficult to budge sometimes is the crap washers under the head nuts. They squash down and bind on the studs and the head. It's worth investing in Mr H's harder washers. Of course, getting the old washers out can be a whole new entertainment but if they really won't come out at least you can drill them out to size again.
Modern composite gaskets don't really need sealant, but do get the cylinder top really clean and flat the head on a piece of wet-n-dry stuck to a flat board (or plate glass if you have it)

Hi Mike. I'm utterly amazed you never snapped any fins off! the correct place to tit the head is the exhaust port and the inlet port. With the exhaut pipe removed you can get a stout piece of hard wood into the port so you can bash the head upwards by hitting the wood vertically (Or nearly so) upwards with a club hammer. Another way is to loosen all the heads nuts equally several turns and start the engine...this will deffinitely loosen the joint. As Pete says, the washers spread and stop further movement, once you get a bit of a gap you just have to keep pushing the head down and pulling it up as fast as you can to gradulaly free it, but never lever it. All other things said & covered by Alan and Pete.

Oh yes...another ingenious method is to feed in nylon rope or thick string though the plug hole and kick the engine over or turn the crankshaft nut.

correction for "Tit the head"...should read:..."HIT the head"...fairly obvious I know but someone might assume I meant "TILT the head"....which I didn't.....CU.

Got my stuck cylinder head off this week using the "Indian Rope Trick" as Les has suggested. It works brilliantly! (But make sure the piston is going up on the compression stroke, so as not to mash the valves!).

Yes, I can endorse the Indian Rope trick as a safe way to get the head off. To be extra safe, I would remove the rockers to ensure the valves don't get tangled with the rope.

PeteF, it definitely was the sealant holding the head, I assure you.
LesH, it was the only option left open to me, the inlet and exhaust ports had had several encouraging whacks followed by several very hefty whacks, the problem was, the head DID move, but did not break the seal, it was glued very firmly with a Black silicone, to break the seal I had to be able to move the head up enough to break the sealant.
Starting the engine wasn't an option, the plug threads have stripped, (helicoil being the reason for removal), plus theres the lack of spark issue to be addressed once it's re-assembled, the rope trick may have done the job, (used that years ago to replace the stem seals on a ford X-flow engine without taking the head off), but that didn't occur, also a lack of nylon rope would have delayed that,
Alan, that's some mornings work,
The bore looks good and the piston crown, apart from a little carbon, looks good so i'm not going to remove the barrel unecessarily, I already have a parts list long enough without adding more cost and want to get it together and running while we have some of this good weather on the go still.
Will check the clearance as you suggest and look at flatting the head as per Petes suggestion, am planning on using the copper gasket as the decoke set I purchased contains one, if that doesn't work very well then i'll look at getting and using one of the composite ones.
I dont know what size front sprocket is fitted just yet, but will wait till it's running and I can give it a good ride round to see if a step up is necessary.
Thanks for the comments and feedback, will pick up some hylomar or wellseal for when it's helicoiled and decoked and i've re-lapped the valves, will take a look at the oversize exhaust valve also, what are the benefits of this? Is the stock one inadequate in it's sealing surface area?

One thing to be carefull of is if the head is really stuck down as this one seems to have been, by using the rope trick you have the potential to break around the small bolt holding the barrel on above the tappet cover.You won't break the bolt, but you can break the top out of the case where the bolt is fitted. I have seen that and it is a case of split the cases and get it all welded back together and then machine the tappet door face and also the deck. I have a set of cases here that have just gone through this treatement