Author Topic: Dynatek leads and stock plug caps  (Read 7824 times)

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Offline HondaMan

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Re: Dynatek leads and stock plug caps
« Reply #50 on: December 31, 2016, 07:55:28 PM »
Hmm...based on the above comments, maybe a 'refresher course' on Kettering design is appropriate here?

The beginning rule: The spark Duration must match the burn rate of the fuel at the compression used. A longer spark that this is a waste of [production engineer's] money (larger, heavier coils are then needed) and a shorter spark can both cause incomplete combustion and enhance ping by letting the unburned fuel coat the cylinder surfaces, making subsequent burn cycles momentarily too rich. This is also often perceived as a backfire in engines like the SOHC4 where a waste spark also occurs while both valves are open.

Honda apparently determined that (like their previous engines) a spark duration around 1.2-1.4mS was about right for the cam timing and RPM range desired: they had TEC design a coil for them with 2 output leads, very similar to the uber-successful CA72/77 design, but smaller and less expensive. The same condensors (0.24uF) were to be used: in order to generate the desired 7500 volt spark at 1.3mS (nominal) with 2.5 amps of current, the Q of the circuit was thus set. Interestingly, the Q of the early (pre-750F) coils is slightly higher than the CA77, probably due to newer winding equipment and the smaller, molded, bodies. As only about 4000 volts is needed to fire these engines, the 7500 volt value is adequate with plenty of margin, allowing solid spark over a wide RPM range (like idle thru 10k RPM) with no "tricky" parts required.

So...once the Q is set, the coils' winding inductance is set according to the size of the magnetic core used, and this determines the number of (wiring) turns needed. To reach the desired charge rate, the wire size is adjusted to make the final (primary) resistance come out to the value needed to consume the power available: this is about 2.6 amps/4.6 ohms on the early 750. This primary resistance controls both the charge and discharge rate of the coil, which is set to meet the desired RPM range (10 to 167 Hz for these revs). This part is simple enough.

The condensor: in the 20th century, almost all automotive condensors were made the same: 0.22-0.26uF, 400v, waxed paper or mylar windings - this design came from the (first successful) 1920s Ford system that the entire world's automotive industry adopted. Only BMW (cars) used a different value, and those where (in today's money) about $200 each, so Honda went with the 0.24uF condensor for economy (no-brainer, there...). This then sets the spark gap in the sparkplugs, to generate a kickback frequency via the high-voltage windings where this value of condensor can be used to set the resonance of the whole LRC circuit. This in turn sets the number of windings allowed/required between the primary and secondary layers in the coil while still achieving the desired spark voltage: and this, in further turn, sets the size of the wire used in the outer windings, and how thick the enamel insulation of this wire must be to make the efficiency high. If the wire is too small, the Q goes up too high and the coil puts out poorly at high and low RPM: if the wire (or insulation) is too big, the Q falls low and the output is weak all across the RPM range. ALL coils suffer this "fight" in their design: in the era of the Kettering Ignition, the only consistent "setting" was the 0.24uF condensor value, so most coils were made to function with it, one way or another.

Now comes the "tuning" part of it: in the CB500 (and all subsequent smaller SOHC Fours) Honda desired more spark voltage at the upper RPM, because the volumetric efficiency of the CB500 engine fell into the above-5000 RPM range. They needed more spark energy "up there" than before (compared to all their earlier engine designs), and the 500/550 also suffers from a tendency to "back-burn' up the intake tract during overlap, due to the long intake runners they used to flatten out the torque curve. So, a weaker spark at low RPM became desirable, and the Q was raised slightly by reducing the number of turns and the wire size in the secondary windings: starting in the 750F0 model, with its higher-RPM cam, they also used those same coils. These are noted by their lower primary resistance of 4.4 ohms (due to larger primary wire being used) and lower secondary winding resistance as well.

Higher Q means higher spark voltage (when running in the resonant RPM range), but it also means weaker starting-speed voltage and shorter discharge time (duration). To improve upon this, Honda changed the resistance in the sparkplug caps. In the early 750 the caps were 7500 ohms: in the CB500 and CB550K1 they were also this value. In 1974 Honda switched all of the Fours to 10,000 ohm plug caps: this made the 750K4/5/6 start better than it otherwise would have, but left it a little shy of spark above 9000 RPM. This was one of the 'detuning' items (along with 3 others) that prevented those bikes from reaching 100 MPH reliably, where the earlier bikes easily passed the Ton. These caps also burned out faster than the earlier ones, because they heated more and because their internal construction was not bonded, but was a carbon "button" captured between 2 copper contacts that burned quickly.

Enter the Dyna hi-output coils: riders not knowing about the plug-cap issue swapped in the 30Kv (3 ohm) coils with (by then) worn-out 15,000 ohm plug caps, and voila'! they got better spark (which they would have gotten less expensively by buying new plug caps...) and the bike(s) ran better, so long as they could feed the extra current to those coils (i.e., only the 750 was successful at this) on a regular basis. BUT...those of us 'in the know' could tell whenever one of these bikes rode by: the AM radio, television, and CB Radios went nuts because the coils were discharging so fast that they made good radio jamming systems. :( They generated so much EMI and complaints from the general public that Congress (DOT) passed new laws against the Japanese motorcycle industry (effective circa 1980) to force them to "quiet" the motorcycle ignition systems. This led to the (less-than reliable, not fully tested) early CDI systems found on Hondas, Suzy's and Kawis of those days. The technology caught up with it by about 1988, but in those in-between years the bikes suffer reliability issues with the spark systems.

By now, the non-engineers out there have glazed-over eyes, so I'll quit... ;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
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Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

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Offline PeWe

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Re: Dynatek leads and stock plug caps
« Reply #51 on: January 01, 2017, 04:08:08 AM »
Mark, thanks for the interesting reading that spice up this forum! :))
More to add to this, right?

Your ignition module.....
I have TEC point plate, your ign module, NO capacitors, Dyna 5 ohm coils, cu wires, NGK 5 kOhm caps.
 I'll try another wire coming season, wire-wound where the conductor is a long spiral. Another way to suppress disturbances as I have understood it.
http://www.gsparkplug.com/7mm-ht-ignition-lead-cable-high-resistance-kevlar-core-high-temp-cable-red.html?___SID=U
I'll make an extra set with new caps so I can swap back to verify differences, good as bad.

Interesting reading here about wires. Important to remember, this is commercial about a brands wire design, wounded spriral design.
 http://www.auroraelectronics.com/Understanding%20Spark%20Plug%20Wires.htm

More wire commercial mixed with own "facts". They also mistrust my next ign. wire's  wounded design ;)
http://www.magnecor.com/magnecor1/truth.htm


I'll try capacitors too. TEC OEM and these that must last forever.
(Capcitors have usualy very high tolerances. I'll try to measure and have mathcing pairs)
http://www.ebay.com/itm/180957550650?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
CBB 224J 630V CBB21 0.22UF


Plugs NGK D8EA has always worked fine on my bike when NipponDenso and Bosch silver stoped work after a few minutes back in the 80's.
I did not feel any difference when using DR8ES-L compared with D8EA back in the 80's. I'll try them again when I have new. Together with boxes stamped Denso X24ES-U, NGK D8EA. Carb jetting eats plugs :( I have a bunch looking like black velvet inside.

I tried Irridium plug Denso IX24 (5372).
They must be colder than D8EA. My engine ran not good with this plug, hesitations and some misfires. Almost black despite lean jetted carbs. D8EA with larger pilots + more fuel screws improved a lot. I guess this Denso Irridium plug is for racing only, not touring around in 3000-5000 rpm on 5:th gear when trottles are almost not lifted at all.

I have NGK's Irridium to test too... DR8EIX (6681)

Denso X24ES-U ran OK too.
Important fact here is that I have mostly used D8EA with correct jetted carbs, Denso irrididium with lean carbs.
« Last Edit: January 01, 2017, 05:42:43 AM by PeWe »
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Offline Deltarider

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Re: Dynatek leads and stock plug caps
« Reply #52 on: January 01, 2017, 08:51:21 AM »
I am not sure but I'd hope the D8EA is identical to the D8ES-L which was a damned good plug. I always used them in my 500 to be on the safe side in vacations with high speed touring (130km/h+).
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Offline garyS-NJ

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Re: Dynatek leads and stock plug caps
« Reply #53 on: January 01, 2017, 01:09:22 PM »
Great stuff mark.

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Offline Deltarider

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Re: Dynatek leads and stock plug caps
« Reply #54 on: January 01, 2017, 01:28:55 PM »
Quote
Great stuff mark.
Forgive me my poor understanding of English but maybe you can tell me now what gives a longer spark duration: 10KΩ or 5KΩ resistors in plugcaps in for the rest the same ignition setup?
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Offline HondaMan

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Re: Dynatek leads and stock plug caps
« Reply #55 on: January 01, 2017, 01:46:50 PM »
I am not sure but I'd hope the D8EA is identical to the D8ES-L which was a damned good plug. I always used them in my 500 to be on the safe side in vacations with high speed touring (130km/h+).

The D(R)8ES-L series plugs were created by NGK at Honda's request in 1972, to reduce the plug-fouling problems in the 750 (there were several other "special" parts made like this, because the 750 Honda was such a HUGE thing in those days, like no one had ever seen since the Ford Mustang in 1964). The heatrange of the D8ES (which was the standard plug then) was increased to an imaginary D7.4ES by making the insulator tip longer, up inside the plug's metal body. As an 'echo' to this in 1973, Nippon Denso (NGK's parent company) modified their equivalent to the D8ES (X24ES) and improved things further by making their tips narrower (thinner): this was not immediately visible, so to make a marketing 'splash' of it, they grooved the ground electrode and dubbed them the "Hot U" sparkplugs, as the [first] X24ES-U. These also extended 1.5mm further into the combustion chamber to help ignite the swirling charge in the 750's engine. The "U" groove has nothing more to do with combustion than a way to easily ID the plugs, despite much hype to the contrary...

The immediate result of these plugs was as desired: the 750 fouled fewer plugs with the "-L" hotter tips, while the thinner X24ES-U tip offered less disturbance to the swirl, and made slightly more power - it was actually enough that it can be felt around 3500-5000 RPM, too. I bought 10 boxes of the ND plugs and offered them in my "performance tuneup" of the 750 in those days, which cost $60 instead of the usual $35, and spent many weeks on my knees doing these tuneups as the result. This was the start of the "Hondaman" thing, as suddenly there was this "Honda man" in western Illinois who could make your 750 beat the Kawi 900 without taking the engine apart. (Hint: it was more than just the sparkplugs...)

One day a California 750 came into the shop for a 1500 mile tuneup (it was actually his first one, still under warranty) that had plugs with a perfect burn color grey on them, instead of the usual dark tan. They were Bosch plugs of the same heatrange as the new "-L' and "Hot U", but were also resistor plugs. The shop that had sold them to him (when his original D8ES plugs fouled out, commonly at 500 miles or so) was out of the NGK, and this was their closest one. They measured 2000 ohms, making the in-circuit total resistance (7500 + 1500 = ) 9000 ohms. I installed new "Hot U" plugs during the tuneup and later tried the Bosch in my own 750 to discover it started better on cold mornings, but otherwise felt like the "Hot U" plugs. I never could find those plugs again, though. I always knew then, when Honda switched to 10,000 ohm caps, that the reason was to improve the low-end torque: later in my research I found out 'why', as outlined above.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

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Re: Dynatek leads and stock plug caps
« Reply #56 on: January 01, 2017, 02:06:47 PM »
Mark, thanks for the interesting reading that spice up this forum! :))
More to add to this, right?

Your ignition module.....
I have TEC point plate, your ign module, NO capacitors, Dyna 5 ohm coils, cu wires, NGK 5 kOhm caps.
 I'll try another wire coming season, wire-wound where the conductor is a long spiral. Another way to suppress disturbances as I have understood it.
http://www.gsparkplug.com/7mm-ht-ignition-lead-cable-high-resistance-kevlar-core-high-temp-cable-red.html?___SID=U
I'll make an extra set with new caps so I can swap back to verify differences, good as bad.

Interesting reading here about wires. Important to remember, this is commercial about a brands wire design, wounded spriral design.
 http://www.auroraelectronics.com/Understanding%20Spark%20Plug%20Wires.htm

More wire commercial mixed with own "facts". They also mistrust my next ign. wire's  wounded design ;)
http://www.magnecor.com/magnecor1/truth.htm


I'll try capacitors too. TEC OEM and these that must last forever.
(Capcitors have usualy very high tolerances. I'll try to measure and have mathcing pairs)
http://www.ebay.com/itm/180957550650?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
CBB 224J 630V CBB21 0.22UF


Plugs NGK D8EA has always worked fine on my bike when NipponDenso and Bosch silver stoped work after a few minutes back in the 80's.
I did not feel any difference when using DR8ES-L compared with D8EA back in the 80's. I'll try them again when I have new. Together with boxes stamped Denso X24ES-U, NGK D8EA. Carb jetting eats plugs :( I have a bunch looking like black velvet inside.

I tried Irridium plug Denso IX24 (5372).
They must be colder than D8EA. My engine ran not good with this plug, hesitations and some misfires. Almost black despite lean jetted carbs. D8EA with larger pilots + more fuel screws improved a lot. I guess this Denso Irridium plug is for racing only, not touring around in 3000-5000 rpm on 5:th gear when trottles are almost not lifted at all.

I have NGK's Irridium to test too... DR8EIX (6681)

Denso X24ES-U ran OK too.
Important fact here is that I have mostly used D8EA with correct jetted carbs, Denso irrididium with lean carbs.

These are some interesting developments in recent years. The wound-wire technique comes from the Apollo Space Program of the 1970s were the wire was wound in a long spiral so that it creates a magnetic field of its own to improve conductance (technical term: 'reduce mhos', which will take you some study time to understand...) of power down a "wire". It uses the magnetic field to conduct energy ahead of the electrons themselves, forming a sort of conduit for energy, thus increasing the amount of current that can be passed through a given cross-section area of wire. Since electrons only scurry across the surface of the wire (about 3 electrons deep), the current-carrying ability (ampacity) of the wire is limited by the amount of surface area available: this is why stranded wires in a given size carry almost 3 times as much current as solid wires, and the more strands, the better. But, this adds cost, and often also weight, the latter which Apollo could not afford. In the spiral-wound conduit, it became possible inside the Apollo capsules to carry 40 amps on a 20 AWG-size wire with almost no heating, and the resulting combination of materials weighed the same as a 12 gauge wire, which would heat up a LOT trying to carry that many amps. The wound-core design also speeds up the passage of the power down the wire: normally the electrons move at about 90-93% of the speed of light, but with the magnetic boost they move closer to that magic speed, without creating extra heat (actually, almost no heating at all). But, it IS expensive to make! In fact, if it had not been for this 'magic' wiring, the ill-fated Apollo 13 would probably not have made it home, as they had only 2% energy left in the capsule when they hit the ocean.

Capacitors: the biggest limitations to the ones used on our bikes is in their mounting: they live on a HOT surface plate that vibrates badly, which destroys conventional electronic-type capacitors quickly. Lots of bulk and extra clearances are needed to package enough windings to survive this, which is why a 0.24uF 400v electronic capacitor is only 20% as big as an automotive condensor. Their loose construction also causes them to have wide tolerances, ranging from 0.20-0.28uF for the typical part, when measured. I used to check each condensor value when performance-tuning the Suzy Triples back in those days, searching for the ones of 0.26uF in the collection for the GT750 in particular: it's coils were biased toward 500-6000 RPM performance, and the engine would do over 8500 if given the spark: the larger-value condensors spread out the bandwidth of their coils and let the street racers go past 8000 RPM much more easily.
;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Deltarider

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Re: Dynatek leads and stock plug caps
« Reply #57 on: January 01, 2017, 11:51:00 PM »
Sparkplugs. Interestingly enough Honda France advised 'newcomer' NGK D8ES-L also for the CB500/550, describing them as autonettoyante (selfcleaning). Honda dealers in Holland who serviced CB500/550s, generally fitted the D8ES-L after break-in period. BTW, I'd like to know what resistor is the more reliable over time: the one built in a plug or the one in the plugcap?
Condensers. In my homebuilt transistor ignition I have a 0.22µF 400V condenser although the original Velleman design has a 630V one. Back then the man in the electronics shop assured me the 400V would be more than adequate. I followed his advice but being a noob in electronics, I still don't know what difference it can make if any and eager to learn, I would like to know. In the pic below left the 400V and right the 630V condenser. I choose the somewhat smaller 400V because it was easier to fit in the box. When I examined the wiring scheme today again (since long), I found out there had been no necessity to have the condenser on the printboard inside the box. I might as well have had it connected close to the coil because in the scheme the condenser is between ground and the 12V- of the coil.
« Last Edit: January 03, 2017, 01:12:18 AM by Deltarider »
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Offline Duke McDukiedook

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Re: Dynatek leads and stock plug caps
« Reply #58 on: January 03, 2017, 06:27:35 AM »
The difference between the voltage ratings of those caps is how much voltage they can handle at a specific temperature with relative reliability. The 630V caps can safely handle more voltage (up to 630V continuous) than your 400 volt cap. The 630 Volt cap would give you a little more safety margin and probably cost a little more. Vishays are considered good capacitors for electronics use.
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Offline Deltarider

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Re: Dynatek leads and stock plug caps
« Reply #59 on: January 03, 2017, 08:17:39 AM »
Thanks Dukieduke. The reason I asked was this: although it is possible, due to induction, for voltage in the primary circuit to be swung up to 300V, I can't imagine spikes to go over 400V. So Velleman choose quite a margin. On the other hand, I seem to remember stock Honda (TEC) condensers were also rated 630V. Unfortunately I can't find back where I've read it. Anyway, my transistor ignition always worked flawlessly with the 400V capacitors.
BTW, maybe you Dukieduke, sir can tell me what gives a longer spark duration: 10KΩ or 5KΩ resistorplugcaps in a for the rest equal ignition setup. I've asked before but had no answer or should I say, an answer that I, not being a native speaker, can comprehend. My bet is: more resistance would mean a higher treshold resulting in a shorter spark duration, but who am I?
« Last Edit: January 03, 2017, 01:02:59 PM by Deltarider »
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Offline HondaMan

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Re: Dynatek leads and stock plug caps
« Reply #60 on: January 04, 2017, 07:58:40 PM »
Quote
Great stuff mark.
Forgive me my poor understanding of English but maybe you can tell me now what gives a longer spark duration: 10KΩ or 5KΩ resistors in plugcaps in for the rest the same ignition setup?


The higher resistance (10K ohm) will give a longer-duration spark than the 5k version, all else being equal.
The OEM setup was halfway between this until value 1974, with 7500 ohm caps (which my OEM Shop Manuals clearly show). On my own 750 I use the 5k caps and 2000 ohm DR8ES-L or DPR8EA9 or XR24ES-U plugs, which comes close at 7000 ohms. It likes it!

You've done a great job of squeezing BOTH of the circuit boards in the box! That's some nice handwork, there. :)
The OEM coils generate a back-EMF voltage spike of about 380-410 volts, shown in my old oscilloscope traces back when we built the Transistor Ignition here: those pictures I took and posted show it clearly.

Here's the "inside scoop" about the 400v/630 volt question: the voltage ratings of paper-wound automotive condensors are rated as "nnn volts @ 1 second duration at 100 degrees C", and they are only allowed to heat up to 80 degrees C for no more than 1 second during this discharge, and it must not punch a hole in the insulation layer in the windings. (whew!). The internal resistance of automotive-style condensors is also quite high (about 150 ohms at the rise-time frequencies caused by the coils), so this lowers the peak voltage that is actually seen inside the condensor itself: in the TEC units I tested this resistance was about 100 ohms at 3kHz, which is close to the rise-time of the back-EMF spike from the OEM coils. The Dyna coils have a faster rise-time of nearly 5 kHz, so they push a little harder on the condensors, so to speak, but usually they will work OK if they are in good shape.

Thus...if the back-EMF is, say, a 400v peak at 3Khz into a 100-ohm equivalent load for 1.5mS, this "chokes" the power entering the condensor by blocking the first 4 amps of back-EMF power momentarily (i.e., 400v/100 ohms = 4 amps). This essentially slows down the spike as it tries to charge the condensor, which also slows down the magnetic field collapse at the coil, storing some of the energy as magnetism until the points close again and drain all this power off. If the points did not then drain it, the coil would resist the next charge because the magnetic filed is polarized opposite the way it needs to be at this point in time (this is where the Dyna S loses the spark energy above 5500 RPM, by switching back to "charge" without finishing off the old charge first). So, putting an oscilloscope on the wires will show a 400v peak voltage spike, but the power actually entering the insides of the condensor will be considerably less, with the outer (larger) layers of windings taking the most heat. This is where they slowly break down over time, and an old condensor, when unwound, will show tiny pinholes in the paper where the breakdowns occur.

When electronic-grade condensors (usually called 'capacitors', same electrical action...) are used, they have MUCH lower internal resistance because they are made with materials that would not survive being bolted onto a hot engine. These materials, like mylar, polyester, or tantalum, are much better at resisting the punch-thru caused by the voltage spikes, but are less tolerant of physical abuse like vibration or dents. To use them, they must be located in a protected area, like a little metal box under the seat...they also act differently, so they need some extra circuitry around them to tune them to match the coils. In particular, they have MUCH lower internal resistance (due to their internal construction), making them heat up MORE if they are installed directly in place of the automotive condensors because the back-EMF kick from the coil penetrates much deeper inside their layers. Fortunately, they are usually part of a protected transistor switching circuit, so the combination of the silicon gate layer(s) of the transistor, connected across the capacitor, provides a 50% reduction of the voltage that appears across the capacitor leads. So, a 400v condensor requirement can be changed to a 200v capacitor rating IF the transistor is also in the same circuit.

The 630v rating of the original condensors was 630 volts at room temperature: at 100 degrees C they were derated to 400 volts instead. Sometime around 1970 the general "rating" specification started including the temperature requirement, so the 630v room-temperature condensor suddenly became the 400v-rated part, overnight. I remember the discussions (and confusion) about this action being bantered about in publications like Popular Electronics and the new solid-state design handbooks that appeared about that time, and it really helped the hobbyists by directing them to the correct kinds of parts they needed for their home-brew CDI ignitions, which were getting popular in those days. I was trained during the Apollo Space Program when these sorts of things were hammered into our young skulls to make sure we didn't strand some spacecraft (or astronaut) somewhere: today it isn't even taught, nor seems to even be known among the engineers I work with every day. :(
« Last Edit: January 04, 2017, 08:44:22 PM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
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Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

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Offline Deltarider

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Re: Dynatek leads and stock plug caps
« Reply #61 on: January 05, 2017, 01:01:21 AM »
Thanks, Mark. I'm confident the 400V condensers will do fine (as they did before, BTW). I'll reassemble my box as soon as I've found the necessary supple wires. Some twenty years ago I had used old wires that I had still lying around and those were already stiff then. Over the years they became even stiffer and since I had not made a pull relief, when I had to replace a battery, one or two wires that had no suppleness anymore, came loose. Somebody advised me now to go for "automotive" wires (what ever that may be), claiming they are more supple.
« Last Edit: January 05, 2017, 07:27:29 AM by Deltarider »
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Offline philgresty

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Re: Dynatek leads and stock plug caps
« Reply #62 on: January 05, 2017, 05:32:22 AM »
I just installed dyna 5 ohm coils and leads, with 5k ngk spark plug caps on marks suggestion to do so.
runs spot on, no complaints.

Offline HondaMan

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Re: Dynatek leads and stock plug caps
« Reply #63 on: January 05, 2017, 08:04:26 PM »
I just installed dyna 5 ohm coils and leads, with 5k ngk spark plug caps on marks suggestion to do so.
runs spot on, no complaints.
I just put your Ignition on the tester, too... ;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline HondaMan

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    • Getting 'em Back on the Road
Re: Dynatek leads and stock plug caps
« Reply #64 on: January 05, 2017, 08:13:11 PM »
Thanks, Mark. I'm confident the 400V condensers will do fine (as they did before, BTW). I'll reassemble my box as soon as I've found the necessary supple wires. Some twenty years ago I had used old wires that I had still lying around and those were already stiff then. Over the years they became even stiffer and since I had not made a pull relief, when I had to replace a battery, one or two wires that had no suppleness anymore, came loose. Somebody advised me now to go for "automotive" wires (what ever that may be), claiming they are more supple.

The most-supple automotive wire is the SXL type, but use it only for the power, ground, and points wires, because it does not have high insulation ability (typically less than 70 volts). For the higher-voltage wires to the coils (between transistor and coil, 400 volt spikes), use the MTW (UL1015) type instead: it has slightly heavier insulation and is heat-resistant (and chemical-proof) and is still flexible. I recently switched to using all MTW on my Transistor Ignitions after I found a supplier who could match the lower-cost price of the automotive stuff with the MTW type, so all my wires now carry 600v rating and I don't have to keep 2 different types on hand anymore.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com