The ignition coil cult

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Re: The ignition coil cult

Post #16 by CYBORG » Mon Nov 25, 2019 9:53 pm

Very interesting, and informative article. I would also be interested in your opinions on the C5 system. I have one on my 78 and would lke your opinion on them

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Re: The ignition coil cult

Post #17 by mikenixon » Mon Nov 25, 2019 10:35 pm

Hi, Cyborg. I think someone asked me about that in connection with another post I made, and I remember admitting I have no real knowledge or experience with the product. Sorry.

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Re: The ignition coil cult

Post #18 by JamesPal » Tue Nov 26, 2019 12:22 am

mikenixon wrote:Appreciate the comment. I hope we can disagree amicably, but I'm afraid I *have* to disagree with several points you've made. I am familiar with that (3- or 4- part) article series also. (I can still see in my mind's eye the RD350 with the big 'ol coils hanging off the front of the frame.) By "crap" I suppose you're referring to the fact that bike coils could not be loaded down and still fire as much as the oil-filled canister type car coil could. While the length of a test gap is a decent indicator of strength, voltage is not directly proportional to performance. There are other variables, and I have explained those in earlier posts. Beyond the voltage needed under the most extreme conditions, plus the surplus that ensures a good margin, more is superfluous. Magic sparks is a myth.

The point I have made in this article and in several others is that the bikes they used in the experiment, and any bike that gets a simple higher than stock ignition coil installed on it, ran/run better because they effectively carbureted better, the coils compensated for carburetion shortcomings (carburetors by definition are compromises, and then add real issues and carburetion can ultimately always be improved), not because the car coils' overcame any ignition deficiency. I don't at all consider OEM Honda point or TPI (electronic) ignitions to be marginal performers. Given components in good health, these ignitions actually work quite well in their intended environment, even when stressed by certain special adjustments geared toward performance (such as high dwell settings on points systems and larger than normal plug gaps on either type). Don't forget that the first season of Honda's 1025 superbikes used completely stock ignition systems, and that back in the day these were new bikes and when magazines put them through the ringer, ignition shortcomings were not heard about. They did not exist.

It is a common theme on some vintage Honda forums that the electrical systems on these bikes are marginal. Seems to be a favorite bogeyman of many. I have preached against this fallacy for many years now. Granted, 240 watts is virtually nothing compared with the over 1000 watts available on many bikes today, but no one stops to think that it was unheard of for anyone to complain about batteries going dead in those days. Yet, today, we have people on forums telling others, "better not put a quartz headlight on your 550, it'll drain the battery", and "it's normal for old Hondas to run their batteries down while riding in town." What nonsense! What utter and complete foolishness! As if some physics laws had changed over the last 40+ years. I am really not interested in trying very hard, but if I had to come up with reasons folks genuinely think these things, I would offer the following. First, really crappy (quality) batteries. A ton of these out there. No one seems to realize how very poor quality low-priced motorcycle batteries can be. Second, equally crappy aftermarket charging system replacement parts. A load of this stuff too, and most forum folks seem to not think twice about using Taiwanese stators and field coils, or of modifying or substituting parts whose function they don't even understand. Third, all 40+ year old bikes suffer from the neglect of their electrical connectors, and this undoubtedly takes its toll on electrical system performance, don't doubt it. Fourth and possibly most significant, there is a riding ethic today among the owners of vintage Hondas that would be totally foreign to those of us who owned these bikes in the 70s, that is, an insistance on operating these machies as if they were pushrod twins, i.e. at less than 4,000 rpm. That just doesn't work, and everyone back then understood it. And of course folks go down the same "this stuff is junk" path with ignition too. Maintained stock systems are marvels of efficiency.

Finally, the advent of electronic ignition. Your comment here is mostly sound, so I will add only that electronic ignition replaced point ignition for one reason only: the five-year clause in the then-new emissions warranty. And even that wouldn't have done it except the feds went one step further and arbitrarily assembled a parts list on which the points were listed as emissions parts. It was not because of their performance, whether in pre-emissions engines or post-emissions ones. There is no performance advantage in any electronic ignition that is simply a transistor-replaces-the-points type. Both are Kettering, with all the same characteristics, strengths and weaknesses.


Nice write up, you truly understand the bike electronics. I would like to respectively add the following. My 1972 CB450 has a 110 watt alternator. That is the spec in the Factory Shop Manual. That is why Honda fitted the original bikes with a 35 watt headlight. In 1972 they upgraded the selenium rectifier to 10% more efficient silicon rectifier. With that the increased the headlight to 50 watts. If a 55/60 watt headlight is fitted the bike will not charge the battery unless is it constantly running above 3,000 RPM. Another thing is the dwell of the ignition system and the inductance of the the coils will affect the current draw of the electrical system. A wider dwell allows the points to be closed for a longer period. This increases the average amount of current required. A lower impedance coil 2 ohms vs 5 ohms will draw more current than a 5 ohm coil. Most electronic ignitions do not publish the dwell of the primary. I have the PAMCO ignition on my 450. I was able to communicate with the designer of that ignition. He told me the dwell was about 25 degrees vs the stock 42 degrees. This allows me to run 3.3 ohm coils. I've swapped the tail light and dash lights out for LED. This gives me back about 7 watts. I put a 55/60 watt H4 headlight in it this fall. I also run a voltmeter so I can monitor the battery. So far so good. I wouldn't say the charging system is crap, but it is primitive. It is a fixed magnet alternator that produces a fixed amount of current based on RPM. I have it working about as well as possible. The bike runs extremely well. I don't think it is possible to foul the plugs. 110 watts is 110 watts. That is what Honda put into their bikes when it was designed back in 1964. I know this forum is about Goldwings and I will return it back to the author. THX

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Re: The ignition coil cult

Post #19 by CYBORG » Tue Nov 26, 2019 10:07 am

mikenixon wrote:Hi, Cyborg. I think someone asked me about that in connection with another post I made, and I remember admitting I have no real knowledge or experience with the product. Sorry.

might be worth a look. I found it to be a lot better then even advertised. The next logical step for cam driven ign. systems in my opinion.

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Re: The ignition coil cult

Post #20 by mikenixon » Tue Nov 26, 2019 11:48 am

JamesPal wrote:Nice write up, you truly understand the bike electronics. I would like to respectively add the following. My 1972 CB450 has a 110 watt alternator. That is the spec in the Factory Shop Manual. That is why Honda fitted the original bikes with a 35 watt headlight. In 1972 they upgraded the selenium rectifier to 10% more efficient silicon rectifier. With that the increased the headlight to 50 watts. If a 55/60 watt headlight is fitted the bike will not charge the battery unless is it constantly running above 3,000 RPM. Another thing is the dwell of the ignition system and the inductance of the the coils will affect the current draw of the electrical system. A wider dwell allows the points to be closed for a longer period. This increases the average amount of current required. A lower impedance coil 2 ohms vs 5 ohms will draw more current than a 5 ohm coil. Most electronic ignitions do not publish the dwell of the primary. I have the PAMCO ignition on my 450. I was able to communicate with the designer of that ignition. He told me the dwell was about 25 degrees vs the stock 42 degrees. This allows me to run 3.3 ohm coils. I've swapped the tail light and dash lights out for LED. This gives me back about 7 watts. I put a 55/60 watt H4 headlight in it this fall. I also run a voltmeter so I can monitor the battery. So far so good. I wouldn't say the charging system is crap, but it is primitive. It is a fixed magnet alternator that produces a fixed amount of current based on RPM. I have it working about as well as possible. The bike runs extremely well. I don't think it is possible to foul the plugs. 110 watts is 110 watts. That is what Honda put into their bikes when it was designed back in 1964. I know this forum is about Goldwings and I will return it back to the author. THX


Very good points and excellent real life examples. What we used to do on the old 350s and 450s is permanently wire the second regulator (these bikes have two regulators, the second one is the headlight switch) always on and that helped a lot. I am sure you know these bikes' stators have two complete system outputs, one is at 3/4 power and the other tied to the headlight switch completes the system for full power. Our bypassing just made it full power full time, much as Honda did themselves on the last iteration of the 450, the 500T. Didn't realize the superseded (silicon as opposed to selenium) rectifier was so much more efficient. Interesting. The actual reason Honda superseded the rectifier was that selenium and germanium rectifiers bled back badly, and also, they tended to overheat, with the visible sign the selenium actually running under the orange paint! Third, they also got shook apart by the bike, since they were bolted together (the diodes) by a single bolt which also doubled as the mounting stud. Oh, and as for that 3,000 rpm... :-) Good comments!

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Re: The ignition coil cult

Post #21 by JamesPal » Thu Nov 28, 2019 7:49 pm

Mike, I didn't do the alternator mod to my 450. The bike has a home made wiring harness and the switches are new. I used 14 gage wire for the harness. The thinking was there would be less voltage loss. It seems to work pretty good. My riding buddy has a SV650 and he complains my lights are brighter than his. Here is a video I shot when I put the 55/60 watt headlight in it.


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Re: The ignition coil cult

Post #22 by JamesPal » Thu Nov 28, 2019 7:52 pm



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