Motorcycle Classics

The Aermacchi Project, Part 5: Fear of Plating

Reader Contribution by Margie Siegal.

The cylinder head is on!

This is the fifth installment of a series detailing Margie Siegal’s restoration of a 1973 Harley-Davidson 350 Sprint. Start at the beginning with Part 1.

When motorcycles were invented in the 1890s, the manufacturers nickel plated some parts. Chrome plating came in the early 1930s. At some point during this journey, motorcyclists started taking parts of their bikes to plating shops to fix or upgrade the shiny stuff. Shortly afterwards, motorcyclists started trading plating shop horror stories.

Most people who repair or own old bikes have heard these stories. The plating shop that lost original, irreplaceable 75-year-old parts worth a few zillion dollars and tried to pretend they had never taken them in in the first place. The plating shop that buffed out the logo stamped on the parts — important to verify authenticity. The plating shop that estimated turnaround time as three weeks that somehow stretched into three months and then wanted triple the estimate.

Right side, showing the teeny tiny cutouts around the cylinder head bolts.

The exhaust system that came with the Sprint I am restoring was pretty crusty and the shorty mufflers were not only not stock and loud, but also ugly. I was lucky enough to locate a decent stock 1-into-2 exhaust and two stock mufflers (Thanks, Brad, and best of luck racing this year!) but they weren’t perfect and needed a rechrome.

Scared by all the stories, I started asking around. Most people who restore bikes have a favorite chrome shop that they may or may not share the name of, like society ladies who go to a special hairdresser. Luckily, one of the guys in the Norton Club has a good connection with a chrome shop and was going to send some of his own parts out, so we combined the order. When my exhaust system comes back, I will let you know how it went. I am not disclosing the name of the shop until then. Don’t tell anyone, this is just between us.

Famous last words: “Just bolt it together.” I successfully cleaned up the rusty bolt that had held the head onto the engine, got the head back from the machine shop, put the rocker boxes together and was finally ready to put the head assembly back on the motor. Friends said, “Great — just bolt it together.” First, there was this little problem of positioning the pushrods. I read the instructions. The service manual helpfully explained that the pushrods go up the tunnel on the right side of the head, the inside one is the intake rod, and I should leave enough space between the head and the barrel for a pair of needle nose pliers so I could position the pushrods in the little cups at the bottom end of the valve adjusters before pushing the head all the way back on the head bolts.

After photo, head bolt cleaned up nice!

I tried. I really did. Getting the pushrods positioned with pliers was just not going to work. I gave up after an hour, fantasized serious injury to the jerk who wrote the service manual, and started emailing for help. Several people suggested I make a little thingamajig with wire. I couldn’t immediately find the right kind of wire, but I did find some stiff cord. I cut two pieces a foot and a half long, looped them around the pushrods and started carefully moving the rods with the cord. A long, thin screwdriver helped with pushrod herding. Those rods did NOT want to go where they were supposed to go, but I finally convinced both of them to get in there.

Corralling the pushrods and making them get into the adjusters took work. They did not want to get in there!

Pushrods in place, I got out my torque wrench and started in on the head bolts. I found that if I took the rocker box end caps off, I could get a 17mm socket on the left side bolts. The right side bolts are in these little caves and barely accessible with my ground down special wrench. I torqued the left side, guesstimated the right side and decided to quit while I was ahead.

  • Published on Apr 18, 2019
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