In the world of classic, small-displacement Honda restoration, there are three companies that provide the bulk of available OEM, reproduction, and aftermarket parts—4into1, David Silver Spares, and Common Motor Collective. While the first two companies offer a more general inventory of parts for all classic Honda twins and fours, Common Motor is a specialist shop that only supports CB350s, 360s, 450/500 twins, and CB550 fours. This narrow focus has allowed the little old bike shop from Texas to develop its own line of parts, upgrades, and accessories for its supported bikes. One such upgrade is the Shockwave Electronic Ignition System, which I recently installed on the CB450. How is it? Well, let's have a look.
Oh, point of order. Before you all go nuts and call me a shill, I get nothing in exchange for this review. I bought my Shockwave with my own hard-earned pennies and CMC knows neither who I am nor that I'm writing this review. That said, if the guys at CMC are listening, call me. Okay, on with the show.
Common Motor Collective's Shockwave is a clever piece of kit. Designed to replace the old, busted points ignition system of an old-school Honda twin, Shockwave is easy to install and integrates pretty seamlessly into the bike's loom. For this review I'm going to walk you all through the steps I took to install it and take you on a little journey wherein nothing goes right with this little project for a week but finally works out in the end.
Gallery: Shockwave Electronic Ignition Install
First, as you can see in the video above, I got everything out of the box on the bench and laid it out for inspection. The Shockwave primarily consists of two modules that contain the "computers" and do the thinking and timing and two matching sensors that mount to a special plate and replace the points. Everything you need to wire and install the kit is included, from brackets, zip ties, and heat shrink to special "posi-lock" and "posi-tap" connectors that allow shadetree mechanics to do all the wiring without the need for cutting, splicing, or soldering. The big instruction manual included with the Shockwave is incredibly comprehensive and includes plenty of full-color pictures and diagrams that even the biggest ignoramuses (like yours truly) can follow.
To install the Shockwave I disconnected the battery and removed the bike's tank, points cover, and stator cover. With the covers off, I pulled the points and points mounting plate as well as the condenser since I didn't need them anymore. Then, when I went to pull the mechanical spark advancer off the camshaft I discovered that it was rusted on. That was the first of my obstacles. I finally got it off with a lot of heat, swearing, and judicious use of a soft hammer and discovered that it was junk. The springs were seriously worn and wouldn't pull the weights back to position once extended. Welp, that explained the weird surging and high-revving problem the bike had.
While I waited for a new (to me, at any rate) spark advancer to arrive from eBay, I did the rest of the install. I assembled the module bracket, installed the modules, and mounted them on the bike. They mount to the right side of the frame on the coil bracket and hang down right under the steering head. I wired everything in using the posi-locks, and tapped the bike's 12v power line with the big posi-tap connectors. These things were a serious godsend and made wiring the system super easy and stress-free. On the downside, they're a touch bulky and make it difficult to hide the wiring under the tank. Eh, it's a good trade in my book.
Here's where another obstacle reared its ugly head. See, I replaced all the old, stripped out Japanese Industrial Standard Philips head screws with CMC's stainless Allen bolt pack. They sell a top end set and a bottom end set for every bike they support, and since mine were all a disaster I figured I'd take advantage of it. I'd already replaced 90-percent of the engine's screws by the time I started this project, and the only ones left were inside the points cover. So, since I was in there anyway and waiting for the spark advancer, I figured I'd go ahead and replace 'em.
The three old screws inside the cover came out no problem, but the fourth (which is outside the cover) refused to come out. Getting the damn thing out of the head necessitated pulling the whole assembly through which the forward camshaft and the eccentric adjusting rod run, which is a pain. With that off the bike, thus began an agonizing process of using heat, impact drivers, drills, a dremel, easy-outs (which, of course, broke off inside the damn screw because LOLEasy-outs)—none of which was able to get that screw out. Finally, frustrated, I just cut it short and filed it down and forgot it. Not, you know, best practices but I'd wasted enough time on it and I figured I could get along without it. (Spoiler alert, I can totally get along without it).
Anyway, after that debacle, my eBay special spark advancer finally came in, so I got to work wiring up the sensors that replace the points. These sensors are possibly the system's weak link, and you need to be extra careful installing them. They're just plastic and resin, so they'll break easily if you hamfist it and overtighten them. They also, during the testing and prototyping phase of their design, had a nasty tendency to work loose as the small mounting bolts backed out of the plate. Loose modules mean your timing goes to hell and you're pushing the bike home. This problem seems to be fixed by now, but CMC recommends copious amounts of blue Loctite on the threads.
Timing the ignition with the Shockwave sensors is extremely fiddly and tedious. It involves all your smallest feeler gauges and probably a solid hour of measuring, turning the engine over, moving the sensors around, and watching the LEDs on the modules flick on and off. That said, once the timing is set it's set, man, and you won't have to fool around with it again. I finally got the timing set but immediately torpedoed myself by cross-threading the right-hand spark plug in the head. This led to a two-day
drinking binge rest during which I got my mind in a better place and ordered one of those fancy back taps to fix the problem. It totally did the trick and I was back in business.
So, how's the Shockwave work? Pretty well, actually! With the timing set and the bike all buttoned up it runs better than it ever has. The surging/revving problem I had is gone, it starts with no choke with just a touch of the starter (or, if you're real cool like I am, on the first kick), and generally makes the bike much easier to live with day-to-day. The only real downside I've found so far is the flashing LEDs on the modules. They light up the front of my engine like a Christmas tree while it's running, and they look kinda tacky at night. Nothing a little electrical tape can't fix, but having the option to turn the lights off after the ignition is timed would be a nice addition.
If you have an old Honda twin and you're looking to modernize it a bit, I highly recommend the Shockwave. I've put about 20 miles on the bike since I finished the install and it works like a charm so far. It's easy to install (and is made even easier by CMC's super good YouTube tutorials), and if your spark advancer isn't junk and you don't make a hash of the install like I did you should be able to do it in an afternoon.
Common Motor Collective's Shockwave electric ignition system runs $200 Yankee dollars, and can be found here on CMC's website. Check out CMC if you have an old Honda twin (or a CB550 Four), and tell 'em I sent you.