Dear Red Dog, I think the lack of lubrication on the front cylinder on pre-1936 Harleys is why the front cylinder runs hotter. Harley went to a lot of trouble to try to get oil mist sucked into the front cylinder, by putting baffles in the cases to increase the vacuum. The recirculating oil bikes run cooler overall and, I think, the rear cylinder runs a little hotter. A hot rear cylinder could be from the reasons you say, or a manifold leak, or it's just more awkward to get a wrench to all the rear head bolts. It really is important to pull the head bolts down again by hand the first time the engine gets hot. I've had a quarter turn on the rear head bolts and half a turn on the front with the metal/fiber gaskets.
I haven't seen copper 7-bolt head gaskets for a long time, although I cut some flat ones for racing. The ridged 9-bolt copper gaskets for 1936-48 VL/UL bikes are available aftermarket. I've heard bad things about the blue teflon 7-bolt head gaskets, have run out of the metal/fiber ones, and am now using an exhaust manifold material that has been good so far.
I haven't seen copper 7-bolt head gaskets for a long time, although I cut some flat ones for racing. The ridged 9-bolt copper gaskets for 1936-48 VL/UL bikes are available aftermarket. I've heard bad things about the blue teflon 7-bolt head gaskets, have run out of the metal/fiber ones, and am now using an exhaust manifold material that has been good so far.
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