BrotherBart said:
If she didn't overheat it before the headgasket blew just get the gasket replaced. Have them check to make sure the head isn't warped while they have it off. If it isn't warped those cylinders are just fine. As far as that goes it only takes a few minutes to stick a micrometer to the cylinders after the head is off anyway.
Lose that dealer's phone number.
AH, but there is the fundamental problem you don't want to go to. You can't just straightedge gap check the beast. Well you can and you might be right and could just as likely be wrong. I did all that, llat as a pancake . What it did have was a gentle swoop across the length that was just enough to make the gasket blow after 5 through 10K miles. I even cut a piece of plate glass and carefully glued a piece of 220 wet dry sandpaper to it and gave it a careful rough hand planing which is what showed me the tiny variance. I carefully sanded that pig just till she touched the lowest part and it lasted longer but blew it again, and again and again. That's why you can't necessarily check it like the regular engines. If you can just get a new gasket tossed on it for a decent price it's worth the one time shot or better yet do it yourself sure do it. On the other hand if it blows again well its pretty much toast in the value dept. You can't get those special double thick head gaskets anymore or at least for a Honda to suck up the slack of such things probably due to the epa ect. Thats why if it's gonna cost you much you might as well just trade it , sell it or invest in one of those engines with the Guarantee. Weird eh? Thats just another reason why with any of these small engines you darned well want to change out the belts, water pump hoses and thermostat long before they could possibly fail. Fantastic engines, very unforgiving of heat.
To check the head for warpage, lay a straight edge diagonally across head and see if any thickness of feeler gauge will slide under it. Then check other corner to corner. Not sure what you are checking with a mike in the cylinders. Wear top to bottom? Find a machine shop to cut head flat again, if you have to.
They are right too about the water pump and timing belt, if it has one.