The traditional Redline Rebuild is was just an engine, but in the case of the Honda Trail 70, Davin is working on the motor as just one part of a bigger machine. The engine on these small bikes goes together fast enough at normal speed that the time-lapse concept is almost overkill. Think we’re joking? This week’s Redline Update proves it.

Before assembly can happen, the cleaning must happen. It’s often an off-camera job simply because it is the most boring part of any project. It might be an uninteresting process, but the results are often worth the effort. For the Trail 70, Davin tried vapor honing, a technique he had not yet used on a Redline Rebuild project. The engine case was shipped down to Ohio, where a friend spent a half hour blasting away years of grime and corrosion. The finished product is gleaming and ready for the roller bearings to be pressed in.

Once a few bearings are in place, the assembly goes quickly. Since the Honda is mainly press-fit roller bearings, there is minimal measuring like the automotive engines Davin is used to. The simple transmission tucks in nicely before the crankshaft settles in next to it. The clutch plates soak in oil for a lunch break before going together to wrap up this assembly session.

Next up is the piston and top-end assembly, and if you don’t want to miss a minute of the process be sure to subscribe to the Hagerty YouTube channel to get notifications when each video goes live.

  • 1
  • /
  • 3

Enjoy Honda Trail 70 stories, opinion, and features from across the car world - Hagerty Media

Share

Of all the skills in Davin’s personal toolkit, paintwork is one that he has not yet perfected. Between the space needed and the careful attention to each small detail in the preparation and application of paint, it’s not something he does often. Luckily, there are experts to step in and help get the perfect finish for the Honda Trail 70 project—because this paint job is even more different than most. Davin loaded up the parts and headed south to Trail Buddy in hopes of getting the perfect finish.

Mark is “the man” when it comes to Honda mini-trail motorcycles. His business specializes—with a laser focus—on reproducing the parts that have disappeared and brings back to life the parts that cannot be replaced. Having painted numerous Trail 70s, he understands the tri-stage paint process better than anyone. He and Davin start by doing some final prep work to the primer that was applied by Traverse Body and Paint. Mark jokes that you only need to sand where you want paint to stick, something that reinforces the nature of the paint process: do it right the first time.

During sanding, Mark notices something that Davin didn’t. The steering stop had been modified or broken at some point in the last 45 years that this bike had been puttering about. No problem; Trail Buddy actually has a new stop on the shelf, and a couple quick tacks with a MIG welder has the frame back in business. Then it’s ready for the first coat.

The final color is orange, but the first pigment from the nozzle is silver. To get the heavy flake buried in the same color as the factory finish, the silver and flake go on first, followed by a dye that builds up to the final color, then it all gets sealed with a couple coats of clear finish. The process is mesmerizing because at each step it doesn’t appear to be moving in the correct direction, then suddenly the color just pops and it is perfect.

With the paint drying, Davin leverages Mark’s time and expertise to tear into the front suspension for fresh seals, boots, and an overall inspection. As exciting as this progress is, Davin is going to have to wait to start re-assembly, because when it’s time to leave, the frame isn’t ready to be wrapped up and put into the car. We can assure you Davin still has plenty of other things to work on while he waits. Be sure to subscribe to the Hagerty YouTube channel and never miss an update from the Redline Rebuild garage.

  • 1
  • /
  • 3

Next episodes

You may also like

Enjoy Honda Trail 70 stories, opinion, and features from across the car world - Hagerty Media

Share

In the latest Redline Update, Davin gets us up to speed on the Cadillac 365 V-8 and Honda Trail 70 projects.

First off, he inventories the Cadillac parts that remain after he disassembled the mill. The lifters show varying levels of wear, with the worst offenders displaying significant dishing. Those won’t be reused. New parts will join the original camshaft, which is being reground. Davin was surprised to find a new water pump; the big casting is pretty complicated, so it’s good to know that the cooling system will benefit from fresh components.

Plenty of the original Cadillac parts will be put back in service, however, and Davin reviews some of the steps used to restore them. For example, the V-8’s pushrods went through the parts washer and then through a tumbler filled with solvent and stainless rods to remove the baked-on oil. Now, they look brand-new. The rocker shaft assembly shows what the valvetrain parts looked like before that treatment. The shaft and its components are going into the ultrasonic cleaner before it heads to the tumbler. Due to the wear on the rocker tips, the rockers will need further work, since the ridges left by the valve stems need to be ground smooth.

Besides the tumbler and other parts washers, Davin and the Redline Rebuild crew rely on a media blaster. A quick trip to that part of the shop shows the valve covers getting stripped and readied for the same paint that will eventually coat them and the rest of the engine.

On to the Honda Trail 70, Davin lists all the new parts that he’s already collected, including clutch plates and a rebuild kit for the stator, plus brake shoes, sprockets, a battery, and an OE chrome engine guard. More and more original parts are going into the bin that’s destined for Jason’s Chrome, which will re-plate all those components in addition to polishing all the aluminum bits, including the intake manifold. Other aluminum parts, like the side case, will be sandblasted and Cerakoted. We also get a peek at the stamped steel frame, which is stripped of its stickers and nearly ready for sandblasting. The rusty split rims are also ready to get sandblasted. If they’re not too pitted, they’ll be powder-coated, but Davin’s lined up replacements just in case.

Next, the video team heads to Thirlby Machine Shop, where the heads get disassembled before being thoroughly cleaned along with the block. As previously discovered, one of the exhaust manifolds is cracked from the center port almost all the way to the collector; Davin plans to drill out the crack and weld up the cast iron. Luckily, the block passes its magnetic crack check with flying colors. Mike at Thirlby will handle boring, honing, and decking the block, making sure to leave the stamping on the deck surface intact. Compared to some of the other projects Davin has brought him, this Cadillac should be a cakewalk.

Finally, Davin reconditions the stock rods by pressing in new bolts, cleaning up the rod caps, and resizing the big end. As parts continue to show up, including the pistons and back-ordered fuel-pump rebuild kit, we’ll continue to bring you progress reports. Make sure you’re subscribed to Hagerty’s YouTube channel so you don’t miss a single one.

  • 1
  • /
  • 3

Next episodes

You may also like

Enjoy Honda Trail 70 stories, opinion, and features from across the car world - Hagerty Media

Share

Probably the smallest project on Davin’s 2021 roster is this orange Honda Trail 70. It’s a running and riding bike, but it’s far from perfect and could use some love. Teardown time for the air-cooled single-cylinder moves quickly, so let’s get to it.

The Trail 70, or CT 70 as it is also known, came stateside in 1969. It was the perfect bike to get those curious about motorcycles absolutely hooked on riding. The diminutive size made it approachable and comfortable for just about anybody, and the peppy four-stroke, single-cylinder engine was both quick and easy to handle, especially with the three-speed transmission behind it. The Trail 70 is a machine that bike people often say “gives room to grow,” meaning that it’s forgiving enough to learn on, but remains entertaining and rewarding as the rider gains experience.

The orange model Davin is going after looks to be in pretty good shape at first glance, but with each step of disassembly this little machine delivers some piece of hidden bad news. Luckily, none of the items found are catastrophic and each can be easily rectified. Before those fixes can take place, however, everything is going to need a good bath and scrub-down.

That’s for next episode, though. For now, go forth and heed Davin’s call to go work on your projects. And if you don’t want to miss the next Redline Update, subscribe to Hagerty on YouTube.

  • 1
  • /
  • 3

Next episodes

You may also like