Not only do I rarely finish projects, it takes forever for me not to finish them. I’m a slow worker. I get bogged down in details and miss the big picture. Details like the front engine mount on Mini Moto Madness. The front down tube on the Huffy is a large diameter pipe and the smaller, cast in semi-circle on the engine crankcase will not fit. The engine kit comes with a steel adapter plate and a U-bolt that fits the fat tube but the thing looks like hell.
I got to thinking and planning, figuring on a chunk of aluminum to fit the two different pipe diameters, holes drilled, cuts made, longer bolts, it was getting out of hand, man. This time I was able to catch myself. What the hell am I doing? Every other mini motor I looked at used the stock mounting plates so I said, “Screw it.” and went with the popular choice. Right there is a two-day labor saving decision.
With the motor firmly in place I spent some time on the chain drive. The rear fender came in contact with the chain so I had to trim it and roll the sharp edge. It’ll need a paint job and stronger brackets but I’m going to wait until the mechanical is done before tackling cosmetics.
It’s almost impossible to get two chains to agree on length so the mini motor kit comes with an idle roller for tension adjustment. The idler also turns the chain angle upwards before the lower frame tubes get narrow, keeping the chain from rubbing. I don’t like the thing but I’m not sure what to do about it. My rear sprocket is slightly misaligned; the chain doesn’t jump off the sprocket but it sure favors the hub side. To center the chain the rear sprocket needs to go outboard 1/16” so that means making a spacer and reassembling the sprocket onto the wheel. I’m also considering adjusting the countershaft sprocket instead. I’ve decided to deal with this situation later.
The pretty chrome exhaust pipe didn’t quite clear the Huffy’s crank arms. I didn’t want to mess up the chrome by cutting and welding the pipe so instead clamped the exhaust flange in the vise and twisted the pipe a few degrees. The pipe twisted beautifully with no wrinkles or kinks. The crank arms clear with room to spare. Sadly, the chrome plating did not go along with the program and delaminated. Pro Tip: Buy the kit with the black painted exhaust. It’s easier to modify for your particular bike.
The ignition coil was a straightforward install. I’ve upped the difficulty rating by routing the wiring through the frame. Most of these bike builds look cluttered with wires and cables. I’ll run the controls inside the frame as much as possible.
The rotor output wiring will also run internally. I’m sure this will end in tears but I saved a lot of time not fabricating a front engine mount so I’m using that time credit to tidy up the job.
The other sloppy area on these builds is the handlebar. Unlike a motorcycle, there is no speedometers or bodywork to hide the throttle/clutch/kill wiring. I’ve drilled holes and snaked the stuff through the bars. It looks cleaner to me. Yes, I’ve weakened the handlebars. I’m willing to risk a crash from structural failure in support of aesthetics. We are all artists and it’s about time we started living like it.
Assembling the Wal-Mart Huffy bicycle was fairly straightforward. When I was a kid, USA-built Huffy bikes were pretty crappy. They were ok if you rode them like a normal bicycle but jumping or rough scrambling would break the frames. Huffys are made in China now and the frame welds look attractive and strong. From the wheels to the handlebars the whole bike looks better than the Huffys of yesteryear. Which is a good thing because I’m strapping a 2 horsepower motor into the frame of the Huffy to see what she’ll do.
The job went well but when I went to spin the wheel to check the sprocket for square the wheel wouldn’t rotate on the axle. As it turns out a small metal dust cap got squeezed between the sprocket center and the hub, locking the wheel.
I dismantled the mess and removed the dust cap. After reinstalling and truing the sprocket I trimmed the dust cap to fit inside the center hole of the sprocket. The bolts for the sprocket are long but you’ll need that length to get the nuts started. One of the 9 bolts in my kit was a bit too short, or I lost the right one so I used a bolt from the junk drawer after cutting it to length. The sprocket to hub deal looks like poo-poo but the sprocket seems like it is attached well and no one complains about it online. We will see.
The sprocket holes are elongated to allow for different wheel hubs but I didn’t like the bit of hole showing so I put ¼” washers on the bolts to conceal the gap. This looks great except that the rear brake stay arm now came in contact with the bolt heads. It’s that tight! A quick realignment in the vise and the arm cleared the bolt heads.
Of course when you alter one item it causes a chain reaction down stream. The re-bent brake stay arm no longer fit between the axle side-plates so I had to make a new clamp to stop the brake stay from rotating under braking. The stock clamp was super thin steel. I figured with 2hp pushing the Huffy to high speeds the clamp needed to be a bit heavier.
The bolt on the stock arm was a tiny #10. That didn’t look so hot to me so I bumped it up to a ¼” size. And since I couldn’t wait for the paint to dry the clamp got a little scratched up.
With the rear wheel fitted back into the frame I started test fitting parts. The rear motor mount clamps securely to the seat post but this frame has a large diameter front tube that is too wide for the bolt centers of the front mount. The motor kit comes with a U-bolt and clamp setup for wide front tubes. I could make it work but it looks horrible and most likely will rattle apart. I’ll have to rethink the front mount. The carb is a little close to the top tube. I will probably run the throttle cable inside the top tube to give it a larger radius bend. The chain run will determine final motor placement.