® sohc4.net

The motorcycle user forum sohc4.net is out of control. This vintage Honda four forum is being held captive at the mercy of a handful of unqualified "experts" who as the queen said, insist that you "believe six impossible things before breakfast." Impossible because they're untrue, made up, unreliable. While many if not most enthusiast forums exhibit some measure of caustic malevolence, sohc4 is way over the top. This site's content is especially egregious in that so many owners of these machines arrive at their virtual doorstep each day, technical waifs really, only to be led even further astray by forum authorities pretending to be experts but in reality dealing in entirely extemporaneous advice. Sohc ("soak") is indeed broke. Bankrupt. Of ideals, of worth, of value. And most of all, of anything worthy of your respect and confidence. Don't believe anything that is said on this forum, but especially about two things in particular. First, about Honda sohc four electrical systems. Whether charging or ignition, the advice of this forum's leaders in this area is just plain ludicrous. Even comical. Second, about proper OEM-spec engine restoration and maintenance techniques. Hardly a word is factual.


Wow. Incredible. This is such a dramatic example. There are multiple errors here. And this is from one of the authorities of this particular forum. And yes, Mark and I have communicated. Go here for a critique of Mark's CB750 maintenance book. Far from an isolated example, this is what you subject yourself to when you believe the things forums tell you. Here are just a few of the facts. First, the factory cast iron valve guides are the longest wearing of any type you could possibly use, and measurably, hugely, longer-wearing than any bronze guides. Second, lead in the fuel has as much to do with this issue as the man on the moon. No vintage Honda four-cylinder was ever manufactured that needed or benefitted from tetra-ethel lead. And oil in the gas? No way. Every professional mechanic knows better.


This is incorrect. The slot in the cam chain tensioner of a CB550 is indeed there for turning. Pro Honda techs use the same factory tool that is used to adjust the valves.

So the engine has to be machined to make the head gasket not leak, huh? Funny I have never had to do that, and no one I know has either. Use quality head gaskets. Vesrah and Athena aren't doing you any favors.


"Doesn't generate enough power to run these coils." Oh, then all of who did this both back in the day and in modern times have been hallucinating. There were so many CB550s running around in the 70s with Gold Wing and Dyna 2-Ohm coils it would make this poster's head spin. And there are plenty today, including my own bike.



This is from another sohc4.net "authority" whose username is twotired. Does anyone actually believe this?



This is astonishingly bad. Like one of those picture puzzles where you are supposed to find out how many things are wrong in the picture. The CB650 does not have CDI. It takes more than knowing the primary resistance to determine an ignition coil's output voltage. Further, output voltage is the potential (and theoretical) peak, not what the plugs will consistently see. And, recommending carbon resistive plug wire for a Honda is astonishingly bad advice.



First, you have no business using "gasket kits". Why would you do that? And, let's be logical for a moment. Does this mean if you don't use those special o-rings and the junk head gaskets the engine will leak oil? All of the mechanics that use neither are doing it wrong and their engines are leaking? You know the answer.


There is so much misdirection on the sohc4 forum. Just a massive amount, like an alternate universe, a rebel outpost. It's not that they have never been confronted with reality; no, they have. But they oppose it, mock it, scorn it. There are guys on the forum that can get 20 more hp than stock out of their engine, that can graft modern day bike suspension onto their 50 year old Hondas. Painting, polishing, resto-mods, all of that. Talented. But, they have a huge blind spot about anything factory, whether specs, procedures, design engineering and quality parts, and especially anyone who has ever worked at a dealership, that individual is automatically the enemy.

One of the SOHC forum "experts" is telling everyone that Honda is essentially lying about their compression figures in their manual, or that at least that you cannot attain them without Honda's tool, a tool that is unavailable. Forum readers are encouraged to not worry about their 100 psi engines, they're really in much better condition than the compression tester indicates, this person insists. Wow. Just wow. First, Honda's tool was also sold to Kawasaki and Yamaha dealers as well, so it may be discontinued now, but it was not that long ago available. This points out the lack of research evident in this post. Second, any decent tool will return the same numbers as the factory's, If the engine is in good condition. Which none of these bikes are. The factory assembled these engines at 170 psi and that is what you get at sea level when these engines are properly rebuilt. Surely someone has glommed onto the fact of valve recession on that forum? But it does not seem like it. No one addresses it, ever. And it is the number one concern for anyone who owns a SOHC four. The forum experts work hard to find excuses for having only 100 psi compression. But it's not Honda lying, and it's the tool's fault only if it's a toy, as any $49 compression obviously is. These folks go on and on about the volume of the tester hose. My Snap-On tester has the longest hose I have ever seen on a compression tester. And it faithfully returns accurate numbers.

Do these folks really think they have discovered something everyone before them was ignorant of? Especially those who made a living at this? It's the same with charging rates on SOHC fours. Instead of calling Honda's system bad and insisting that you can't even put a high performance ignition coil on a CB550 without the battery going dead, why aren't they instead considering the Walmart battery and the two dozen fifty-year-old canon plugs and the Chinese charging systems parts that virtually all of these guys' bikes suffer from? Not to mention so many of them trying to ride their CB550s as if they were old pushrod Harleys, never getting over 3500 rpm? No one stops to think. Can they really believe folks who owned these bikes when they were new suffered the way they tell the forum visitors they will suffer? It boggles the mind. There is such as thing as high performance, but it has to start with low performance, that is, get the stock stuff right first. If you disdain stock specs and engineering, do you really think you are going to exceed that, when you don't in many cases even know what it is?

I realize of course the whole forum is not at fault. It's made up of mostly innocent people. As with any organization, it's the leadership that is responsible, that sets the tone, the ethic, of the group. And that's what I have against the forum. Innocent people being totally mislead by tin gods, very vocal individuals pretending to be authorities but in reality virtually clueless.

Recommended reading:
An assenting voice
Forum backwardness
Lies from the ether
Real issues
Don't touch
Powersports orphans
Forums and me
They hate Honda
Where did the compression go?
Reasons for low compression
Valve recession

Last updated October 2022
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