Ask the SOHC/4 forum whether your CB550 needs an electronic ignition and you won't get an answer — you'll get a fight, and it's a good one. It has been running in one form or another for the better part of two decades, and it splits neatly into three camps: the Dyna S loyalists, the Pamco converts, and a quieter faction that never gave up their points at all. What makes the argument worth reading isn't who wins. It's that the veterans keep dragging every newcomer back to the same unglamorous part hiding under the points plate — the one that decides whether any ignition, stock or electronic, actually keeps time. Here's what the community has worked out.
Three camps, one bolt-on dream
The dream is always the same: throw away the points, never set a gap or a dwell again, and let the bike start on the button and pull cleanly forever. The three ways owners chase it are genuinely different animals, and the forum is careful about the distinction.
The Dyna S is the old reliable — the unit most people mean when they say "electronic ignition" on a 550. It's a magnetic trigger that replaces the points but keeps the stock mechanical advancer. That's the key detail everyone glosses over: a Dyna S doesn't do anything about timing advance, it just triggers the coils electronically instead of with contact points. It's earned its reputation as the performance-and-reliability standard, and most people who fit one are happy. The recurring caution in the threads is about what's inside it — the components are surface-mount and not automotive-rated, and every so often someone reports a unit that drifted or died after a few seasons. It's not common, but it's common enough that the veterans tell you to keep the old points in your kit bag.
The Pamco took the opposite approach: a fully self-contained system with its own electronic advance, which means you can retire the mechanical advancer entirely. Its designer used to post on the forum directly, and one of the more interesting technical detours in the archive is his explanation of why the unit moved from its original optical (infrared) sensor to a modern Hall-effect chip — a monolithic solid-state part with its own built-in voltage regulator that holds a consistent output from roughly -40°F to 300°F, with no discrete components to degrade with heat or age. It's genuinely clever engineering. The catch today is availability: Pamco is no longer in business, so this is increasingly a "if you can find one" option rather than something you order new.
The third camp barely counts as a conversion at all. The Hondaman transistorized ignition — built by longtime member Mark Paris — keeps your points, but relieves them of the one job that wears them out. Instead of carrying the full coil current (which is what burns and pits the contacts), the points become a low-current switch that simply tells a transistor when to fire. The points stop eroding, the gap stops drifting, and you essentially never touch them again.
The part the whole argument keeps circling back to
Here's the punchline that surprises newcomers: on these bikes, the points are rarely the real problem. The advancer is.
Under the points plate sits a mechanical spark advance unit — a pair of spring-loaded weights that swing out with engine speed to advance the timing, then pull back at idle. After fifty years, the pivots gum up with old grease, the springs sag, and the weights either stick or flutter. The result is timing that wanders: fine at idle, erratic under load, impossible to set consistently no matter how carefully you gap the points. And this is the trap the forum watches people fall into over and over. A rider fights a bike that won't hold timing, blames the points, spends real money on a Dyna S or a Pamco... and discovers the new box triggers off — or bolts onto — that same tired advancer, so nothing improves.
The veterans' correction is blunt and nearly unanimous: service the advancer first. Pull it, clean the old grease out of the pivots, check that the weights swing free and the springs still snap them back, add a whisper of fresh light grease, and set your timing on points. Only then are you in a position to judge whether an electronic ignition adds anything — and to know that if you go with a Dyna S, you're bolting it to a mechanism that actually works. This is also the single strongest argument in Pamco's favor and, for the points-and-transistor crowd, a reason the Hondaman setup appeals: fewer worn mechanical parts left in the timing chain means fewer things to drift out of spec.
Don't forget the charging system it all hangs off
The other thread that runs through every ignition discussion is the 550's marginal charging system, and it bites people in a specific way: coils. When you fit a new ignition, it's tempting to also fit hot, low-resistance coils — 3-ohm units in place of the stock 5-ohm arrangement — for a fatter spark. But lower resistance means higher current, and the 550's charging system doesn't have much headroom to give. Dynatek themselves spec 5-ohm coils with a Dyna S for exactly this reason. More than one "my new ignition drained the battery" thread turns out to be a charging system that was already living hand-to-mouth, pushed over the edge by greedy coils. If your stator and rectifier aren't in fighting shape, sort that before you start asking the electrical system for more.
So which one should you buy?
The honest synthesis the forum keeps landing on is less about brand loyalty than about temperament. If you want the most proven, widely supported bolt-in and you don't mind that it rides on the stock advancer, the Dyna S is the default and it works — just service that advancer and keep your old points as a roadside spare. If you specifically want to delete the mechanical advance and you can source one, the Pamco is the elegant answer, with the caveat that support has dried up. And if what you actually hate is maintenance rather than points as a concept, the Hondaman transistorized unit is the sleeper pick: it's been in service on these bikes since the mid-2000s with a failure rate low enough that owners talk about it with something like disbelief, it's warrantied by a builder the community trusts, and it has the one feature none of the others can match — if it ever dies on the road, you swap a couple of wires back to the points and condensers you never removed, and ride home. For a fifty-year-old bike far from a parts counter, that reversibility is worth a lot.
What none of them will do is fix a bike that isn't running right underneath. An electronic ignition is a timing trigger, not a tune. It won't clean a carb, it won't heal a weak stator, and above all it won't compensate for an advancer that's sticking. Get the mechanical spark advance right, get the charging system honest, set the timing where it belongs — and then the box you choose is almost a matter of taste.
Read the threads
This is a distillation of years of freely shared, hard-won experience from the SOHC/4 Owners Club forums — including the long-running Pamco ignition discussion where the designer himself weighs in on sensors and advance, and the Hondaman ignition & advancer thread that keeps steering people back to that worn advance unit. If you're weighing a conversion, read them in full — the nuance in the actual back-and-forth is worth an evening. And since the club runs on donations, if that archive saves you a headache, kick a little back their way so it stays online.
Ignition work on a 550 is really electrical work, and electrical work is where a clean build lives or dies. A tidy, reliable spark wants a tidy, reliable system around it — which is exactly what the Thirteen Motorcycles CB550/CB500 catalog is built for: under-seat electronics trays and center-stand battery boxes to relocate and protect the battery, coil and ignition mounting hardware to keep everything anchored against heat and vibration, and the bits to route a harness that won't chafe or sag. Sort the advancer, sort the charging system, pick your ignition — then build the rest of it to match.
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