Ouch! Unfortunately, had you posted before hand, we could've told you that was most likely going to happen, and saved you some money! From your description, the pitted surface was almost certainly due to a reused head gasket, allowing coolant to seep out from under it.

The only solution now is to replate (or replace) that barrel. Having it replated may well see yet another "skim" taken off the top of it, as many platers seem to like to do, so you will need to carefully measure it up once it's returned.

No inherent problems with using two base gaskets on that barrel, other than skimming off the top of the barrel and then lifting it back up with thicker gaskets will alter the port timing a little. If you're running a stock road bike, it's going to be of little consequence, but if you're going for performance, at best it's not going to help.

It's already recommended to run a 0.6mm base gasket on the front MC21/28 cylinder (once delimited) to reduce the chances of detonation, but by the sounds of things, a 0.6mm gasket is only going to bring you back somewhere near stock. If you have the barrel plated and they take yet more off the top, and you're using crap low octane US unleaded, you're probably better off now sourcing a good, standard used barrel, in my opinion.
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Andy.
NSR-WORLD.COM

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