I picked up an old dirtbike and it looks like the head gasket is no longer produced. I can get NOS but they want more than I have in the bike and the rest of the engine is an unknown. The existing gasket is torn but the metal cylinder ring looks good. If I used a good quality gasket sealant do you think I'd have any luck reusing the old gasket? I don't want to drop any money on this project until I know it runs and shifts.
Make your own. Parts stores should sell the material in different thickness. Find out what that should need, trace, and make your own. That's what I would do for any other gasket and I think is worth a shot.... at least after someone backs me up... 
... guys?
http://www.thumpertalk.com/topic/523640-make-your-own-gaskets/
Its been done. Just gotta select your material.
What make/model/year bike is it?
Is there any market in having your local waterjet/lasercut guy make you 50 of them?
Sounds like its fiber with a metal combustion ring. If you post more info I maybe able to help. Year , make, model etc.
In reply to 44Dwarf: That's exactly what it is. The bike is a 1972? Husky RT250. As I stated I can get a gasket set but they want more than I want to spend on this project at this point. Half of the gasket is stuck to the head the other half is stuck to the block. The metal combustion ring is stuck to the block and is in good shape.
Air cooled right? Is there a relief groove for the ring?
In reply to Kenny_McCormic: Yup. Air cooled. I don't know if there's a groove in the block but the head is flat.
Wonder if you could have the head/barrel cut for a fire ring then use a homemade gasket. If the gasket you make doesn't have a fire ring it won't last long.
Just realized the head gasket on the punky buellster is made with shiny graphite or something and I don't think it uses a firering so I might be full of E36 M3. You'll figure out something.
edit in to say the buell headgasket does have a fire ring.
I'd try cutting a gasket out of very soft copper then, or if you think it will handle the compression without going to race fuel, lap the head to the jug and use race grade (250 Celsius rated) hylomar.
This is all assuming the jug hasn't got a groove in it.
I don't recall 72 using a head gasket at all...but if there's one there and you found a part number it must be real. How much is to much? Have you tried Hall's cycle?
Or you just use some copper gasket goo and run no head gasket at all. I've done that numerous times on air cooled engines, and gotten away with it almost every time.
foxtrapper wrote: Or you just use some copper gasket goo and run no head gasket at all. I've done that numerous times on air cooled engines, and gotten away with it almost every time.
That's what I did tonight. I'll let it set up and try starting it tomorrow.
So, how's it holding?
Back at my last job we had a CNC router. I helped a coworker of mine draw vector file of his gasket, and we took an appropriately thick sheet of copper and cut out the gasket. He then annealed it, put it on the bike, and it worked great.
If you're good with a drill press, jigsaw, and a handheld router the whole thing could be replicated with a little more time and patience.
I don't know old huskies, but when I was a kid I had a couple air cooled Kawasaki KDX 200s. They had copper head gaskets, and no relief in the jug or head. I reused the head gaskets at least one time each, and as a young teenager I knew nothing about re annealing them.
If your Husky doesn't have a relief for a fire ring, I think you could successfully make a copper gasket using the old gasket as a pattern.
FWIW, third world mechanics do this all the time.
we used to cut oil can lids out as kids....when was the last time you seen an oil can?
The bike is running. Copper gasket goo seems to be holding up fine.
Just a bit of warning. Now you know it runs, shifts ect you may wish to pull the head and measure the squish clearance using some solder. Often production bikes had to big of a squish but if you don't have enough you'll not want to ride it hard, only way to know is to check.
like this link about 1/2 way down shows a pict http://www.rb-designs.com/squish-band-test.htm
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