Two-Up John Harmon Shovelhead Motorbike
Two carbies, one on the wrong side. Two exhaust pipes, one on the wrong side. Why does this chopper look so right…
I BOUGHT the bike back in 1987 and the motor in 1999, then basically designed the whole bike around the motor and those carbies. It was basically a stock standard, 1200 cc Shovel to begin with which I bought mainly for the five-speed gearbox. I virtually made every nut and bolt on it including the triple trees, risers, axles, swingarm, manifolds for the carbies, side pans and inner primary.
The motor was originally built by John Harmon in America back in the early ’80s. He produced 95 of them then got bone cancer and died. It uses a 1200 Shovel bottom-end with 1200 rods. It was a special motor because it’s 120 cubic inches without being stroked—that’s why it has massive cases and barrels—the pistons are huge.
John Trease in Melbourne re-did the motor for me. He modified the heads, made a cam to suit, installed Carrillo rods and Velvet Touch hydraulic roller tappets.
After John finished the motor, I found all this information on the internet about Harmon motors. I found out it’s only supposed to be 6:1 compression because you kick-started a motor 20 years ago.
I didn’t want to have an electric start. I thought I’d go old school. I believe if you can’t start it, you can’t ride it. But John increased the compression ratio and if you tried to kick it over, it wouldn’t move. So we started without the electric start but now it’s got one.
It spent a lot of time at Doc Hogs in Melbourne. They made the engine mounts and gearbox plate which were a nightmare. They had to be heavy duty to compensate for the big bore motor. They also made the back guard and back struts, the seat pan, the oil tank, front scoop, etc; they re-modified the stuff that I had on it, and put it all together for me.
A guy by the name of Michael did the exhausts. It’s got twin coils and an electric fuel pump to feed the twin Weber carbies.
Not only do the carbies run out on different sides, but so do the exhaust headers. I don’t know why John Harmon designed the front exhaust to run out on the left. Maybe it was for drag-racing; maybe it was just for looks.
The nitrous oxide bottle is an additional breather because the pistons are so big. They’re four inches wide and they push a lot of air. About 20 years ago they found out that if you get too much crankcase pressure, the oil going up the heads can’t come back down. So what we’ve done is open up the breather to let the oil out of the heads which feeds down to where the breather comes out of the motor and up to the top of nitrous oxide bottle, then back into the oil tank. It gives me the advantage of having a smaller oil tank and it helps the breathing system.
The plumbing for the big motor was extensive. A lot of time and effort at Doc Hogs went into getting the plumbing neat and tidy.
The original frame was made one inch wider; the back shocks have been pushed out one inch and the front-end is one inch wider. Doc Hogs had one look at the frame and decided it wasn’t strong enough for the big motor. They gusseted every corner, every joint.
The hand-controls are from Performance Machine. The hydraulic lines for the front brake and hydraulic clutch go right through the guts of the risers, into the top triple tree, and exit from the bottom triple tree.
The triple trees are raked because I want to register it and because the bike is too long.
The foot controls are made from stainless steel; the side-stand was made to match.
Pro Styling painted it for me. I asked for candy apple ghost flames but I left it up to him and he did a bit of a burgundy candy apple and mixed it all in. Doc Hog helped come up with the colour scheme because, even after 20 years, I couldn’t work out what colour I wanted.
I’ve been doing this bike for a long time but I haven’t ridden it yet. We started it up at Dog Hogs with the long pipes. I was standing 10 feet behind it and it was hurting my ears.
Photos by Wall 2 Wall; words by Doc
Karlee is on a Working Holiday
TODAY’S SHOOT with the Harley-Davidson was awesome. My dad has a Harley and I go for rides on the back. I love it.
I’m from Canada and I grew up on a farm so I love riding horses. I’ve been in Australia for three months on a working holiday and I’ll travel around until about January. I’ll probably go to Queensland first to follow the sun.
I’ve done a lot of modelling. I was scouted in Vancouver because I’m so tall and I’ve been doing it for about seven or eight years now. I’ve done a lot of promo work as well. I’ll hopefully do some more modelling here as well and just live it up for a while.
I’ve had heaps of fun; thanks for having me.
Hi, I have a Harmon 120 unassembled engine but it’s missing the rear head & barrel. Engine # FAB389018. If anyone knows of a wrecked or blown up engine
sitting under a work bench for 1,2,3 decades & would be interested in selling,
so i can get started on a build, Mobile: 0427764622