Bigbill
Husqvarna
Pro Class
Isn't that location of that Mark is close to where the opening of the skirt on the piston is? That's a machining mark the more I look at it. See the other mating mark to the left of it. They cut a circular clearance for the piston skirt so they clear the rear and front in the block and the cutter just touched the sides a tad.
Remember to do the leak down test after the engine is reassembled with new seals and gaskets to make sure nothing is leaking.
I learned the hard way about doing the on the bench leak down test. We had a 125cc honda where the PO was prying off the cylinder and it mushroomed the material in the base gasket area enough to cause an air leak. The leak down test showed why it was running lean. It pays to recheck to make sure it's right. I use a fork pump to do the leak down test.
Remember to do the leak down test after the engine is reassembled with new seals and gaskets to make sure nothing is leaking.
I learned the hard way about doing the on the bench leak down test. We had a 125cc honda where the PO was prying off the cylinder and it mushroomed the material in the base gasket area enough to cause an air leak. The leak down test showed why it was running lean. It pays to recheck to make sure it's right. I use a fork pump to do the leak down test.