Project 1970 Honda CB350 — Part VIII

It's time for the big reveal: Our 1970 Honda CB350 is finally done!

Project Honda CB350

Our 1970 Honda CB350.

Photo by Richard Backus

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The is the eighth and final part in a series on our 1970 Honda CB350 build project. Read Part I, Part II, Part III, Part IV, Part V, Part VI and Part VII for earlier stages of the project. You can also watch video of our Honda running for the first time.

Of all the projects we’ve done over the years, our 1970 Honda CB350 took the longest and in some ways was the hardest. Our goal, as much as we could, was to keep it looking stock and original while also giving it sensible upgrades to make it a rider as well as a looker. We think we’ve succeeded on both counts.

This CB350 project has been a real education. Except for our very first project, the 1971 Triumph TR6C we put back on the road almost 10 years ago, every build we’ve done has been a custom. There’s a certain chickens@#% logic to that: You don’t have to like what we’ve done, but you can’t say it’s wrong, because it was never supposed to be right. Adding to the allure of a custom is the simple fact that correctly executed restorations paying strict attention to originality are just plain hard. There are myriad details that have to be right if it’s really going to be a proper restoration, and getting any one of them wrong invites a tongue lashing from the cognoscenti.

Sticking to the facts

Yet for us, this bike has come close to being a restoration because this time we tried, as much as we reasonably could, to stick to the rule book and keep the bike mostly stock. That “reasonably” qualifier is important, because from the outset there were certain deviations from stock we knew we’d make.

First up was fitting our Honda with an electronic ignition. Stock points systems work fine, but they’re fiddly, and if you’re really going to put miles on there’s just no reason to keep them and not convert to electronic ignition. We turned to Honda specialist Charlie O’Hanlon at Charlie’s Place, installing his custom-made electronic ignition along with his Dyna ignition coil conversion, complete with custom mounting brackets and plug leads. It’s a straight-up conversion, and one of the best things you can do to an old Honda twin you actually plan on riding to ensure trouble-free running.

To make sure we’d always have proper voltage we also swapped the original — and no longer available — selenium rectifier and regulator setup for a Charlie’s Place regulator/rectifier, along with a lithium-ion battery from BikeMaster for a usable boost in cold cranking amps and a huge savings in weight, the lithium replacement coming in at 2.6 pounds against 9 pounds for a standard lead-acid battery.

We turned to Hagon for shocks, opting for their Classic I Chrome series. Aesthetically they’re very close to the originals, and they’re miles ahead in terms of performance. As good as Hondas are, their shocks were generally sub-standard even when new and just didn’t hold up to long-term use, whereas the Hagons will last years. We had to make one minor adjustment to fit the Hagons, installing a 1/4-inch spacer to shift the chain guard away from the shock. The Hagon shocks use a longer spring than the stock unit, placing the spring pre-tensioner lower on the shock body, where it pushes against the chain guard. The black plastic sleeve we used is invisible and the slight realignment of the guard completely unnoticeable.

Other deviations from stock include the mufflers we picked up from EMGO. We know they don’t look stock, yet they look right and don’t detract from the CB’s original appearance — and at $60 a pop from Dime City Cycles they’re an economical option. We also had Buchanan’s Spoke & Rim re-lace our wheels with stainless steel spokes, although at their suggestion we kept the original D.I.D. rims. We’d planned on new replica rims, but Buchanan’s says the quality of the originals is hard to beat.

There are a few other non-stock points, likely quite obvious to Honda collectors, but not necessarily anyone else. The control cables — clutch, brake, throttle, speedometer and tachometer, and all from Barnett — are black instead of the original gray, an unimportant point to us, especially in light of their high quality. The handlebar switch gear was in pretty bad shape, so we stripped both assemblies down, media-blasted them and then painted them satin black. The color’s not stock and we didn’t detail the lettering in the housing. We also painted the headlamp shell satin black instead of body color, which we think lends a little more color contrast to the bike, putting the attention squarely where it belong on the beautiful paint job executed by Marbles Motors.

We originally wanted to paint the bodywork green, but eventually settled on Candy Gold/White, and the finished result is just spectacular. We sent Randy Marble a box of tired-looking painted bits, the tank in particular in pretty bad shape; what we got back was flawlessly painted bodywork that looks so good we were scared to put it on for fear of scratching it — which we did, although thankfully you have to know where to look to see it. One of the many little pains in final assembly was installing the new chrome-capped side cover grommets. At first blush the grommets seem impossibly big for the holes in the side covers, and initially we simply couldn’t get them installed. Eventually — and with the help of some light lubricating oil — we coaxed them into place, but not without very lightly nicking the paint when one chrome cap touched the side cover while angling it into place. As the old song says, the first cut is the deepest. Luckily, the original emblems were in good shape, needing only basic cleaning and prep before installing on the “new” tank and side covers. Details like those really bring the bike together, and the final look is just fantastic.

If you’ve been following this project from the beginning you know that the seat was a surprisingly major challenge. As it turns out, seat pans for the early 1968-1970 CB350s are thin on the ground. Unique to those years, they hinge at the back, not the side as on later bikes, and apparently all of them rust out like the one that was on our bike. Fortunately, we finally found a usable one thanks to Vintage Motorcycle Rescue. It still took a bit of grinding and welding to get it back to form, but it was all worth it looking at it now with the new foam and cover from Sirius Consolidated stretched in place. The foam’s a little taller than stock and a little softer so it’s not a dead ringer for original, but the final look is really good.

Final assembly

Final assembly is always nerve wracking. After months of prepping, overhauling and painting, it’s inevitable that something doesn’t fit right or doesn’t want to go together, and there’s always some surprise lurking in the shadows.

One surprise was discovering that early Honda CB350 instrument mounts are handed. Assuming — always dangerous — that the mounts in our stash of parts were correct, we sent them off with all our other chrome bits to Quality Plating for re-plating. Like all the chrome work, they came back looking amazing (they’re stainless steel from the factory, but we thought they’d look cool in chrome). But when we finally mounted the speedometer and tachometer to them, the tach, which is on the right side, was clocked wrong, it’s 12 o’clock position at roughly 2. It was only when we checked the parts schematic that we discovered that Honda, for whatever reason, decided to make each instrument base — and by extension each instrument mount — unique, with a distinct left and right hand setup. Who knew? Well, now we do, but with replacements unavailable we were left floundering until local friend of the magazine Lynn Metzger informed us he had a stash of old CB350 parts, including a good set of original instrument mounts. Nice.

Actually, Lynn saved us twice, because he also had an original handlebar, something we’d had no luck locating. Actually, we could find one, but every one we found turned out to be bent just like the one that came with our bike. The CB350’s bars are unique, with a thicker center section between the bar mounts and the ever-challenging internal wiring. We were all set to install wider and lower replica CB400 Super Sport handlebars from EMGO when Lynn stepped up with an almost perfect original handlebar. Nice again.

A minor mystery centers on the headlamp brackets. As near as we could tell, we were the first to ever strip our Honda down to the frame. The body work appeared to be completely original, yet on reassembly we discovered a weird inconsistency in the headlamp brackets, with the right bracket reaching forward approximately 1/4-inch or so farther than the left, skewing the headlamp to the left. We haven’t had an opportunity to compare what we have with another CB350, but looking at original parts available at David Silver Spares suggests that Honda did change the brackets, as the part numbers change between certain years. We’re scratching our heads a little on that one.

We still have a few minor niggles to attend, including replacing the front turn signal stalks. They’re a lot more pitted than we appreciated and we should have sent them off for chrome plating with everything else. Frankly, we spaced them out, a short-sighted mistake that can happen pretty easily when you’re a neophyte at restoration work. Seasoned pros know exactly how to proceed to make sure they have as few surprises as possible.

Outside of some finickiness with the right side switchgear the electrics hooked up just fine, and our decision to keep the original wiring harness appears to have been rewarded, as every component is getting power and, outside of the neutral light, works. The horn honks, the turn signals signal, the brake light lights, the headlamp illuminates and the starter spins. 

Ah yes, the starter. That brings us pretty much to the end of our project and leads to the big question: After all this, does it run? Well, you’ll just have to see and hear for yourself at MotorcycleClassics.com/CB350-First-Run.

We’re pretty happy with our Honda, and all things being equal, we think we did okay. We had lots of surprises at the front end — the broken engine mount casting chief among them — but that’s just part of the landscape of old motorcycle restoration, or any kind of restoration for that matter. It’s been a fun process and the finished bike looks cool; but the coolest part of this project is what comes next, because instead of giving it away in a sweepstakes, as we have all our previous builds, this time we’re going to auction the bike off for charity.

That’s been a stated goal from the outset, and Bonhams has enthusiastically agreed to auction it off for us at their annual Las Vegas, Nevada, vintage bike sale on Jan. 26, 2017, with 100 percent of the proceeds going to a yet to be named motorcycle benevolent fund. The motorcycling community has been very good to us — it seems right that we give something back. MC


Project Honda CB350 Suppliers

Avon Tyres: Front and rear Avon Roadrider tires
Barnett Clutches & Cables
: New clutch, brake, speedometer, tachometer and throttle cables, new clutch discs and springs
BikeMaster
: Drive chain, lithium battery, passenger pegs
Bore Tech
: Gasket and seal set, oil filter/clutch spanner tool
Buchanan’s Spoke & Rim
: Re-laced wheels with new stainless steel spokes
Charlie’s Place
: Electronic ignition, ignition coils and mounts, voltage regulator/rectifier
CMS
: Reproduction and NOS Honda parts
David Silver Spares
: OEM replacement air filters, carburetor intake mounts, rear gas tank rubber
Dennis Kirk
: Front and rear wheel bearing kits, reproduction fuel petcock
Dime City Cycles
: Fork seals, front and rear sprockets
EMGO
: Replacement mufflers, rear view mirrors, handlebar
Forking by Frank
: New fork tubes
Hagon Shocks USA
: Classic I chrome shocks
Marbles Motors
: Paint prep and painting
Quality Plating
: Custom chrome plating
Sirius Consolidated
: Master carb rebuild kit, seat foam and cover, chain adjusters, chrome fasteners, front and rear brake shoes
The Pit Stop: Aluminum engine welding — (785) 887-6626
Topeka Custom Coatings
: Custom powder coating
Vintage Motorcycle Rescue
: Used seat and headlight bucket, battery cover