Topic: Transistorized Ignitions, aka Hondaman Ignition in Dual, Single, and now Triple!

[RAFster122s]

Cosmoline, concentrated animal fats...who knows what they use... Maybe old Chinese AK "bluing" material?
Oh, they make you see red! And, if you hit your head when you fall, then you might see blue and black, purple, green, and yellow and other "pretty colors" from the bruising.

Thanks for the info...

David

[jspeed]

My 550 ran great with your ignition system. it stopped working i checked the the power supply and it gets 12v. and ground is good what should i do. also checked all connections no fire had to go back to points. need help.

[HondaMan]

My 550 ran great with your ignition system. it stopped working i checked the the power supply and it gets 12v. and ground is good what should i do. also checked all connections no fire had to go back to points. need help.

If you have a voltmeter you can check the voltage at the points: Open the points (like maybe stick a business card in them to hold them open) and turn on the ignition, then check with the meter across the points contacts. There should be at least 7 volts, and may be as high as 12 volts (battery voltage).

Then bypass the box: unplug the Yellow/Blue/Orange/Purple wires at the back of the engine and plug the points back into the coils right there. This will tell you if the bike is still OK: if it runs again, then it may be the box: if not, then it is the bike itself. Please get back with me, we'll solve it.

[HondaMan]

My 550 ran great with your ignition system. it stopped working i checked the the power supply and it gets 12v. and ground is good what should i do. also checked all connections no fire had to go back to points. need help.

Well, now I am more puzzled: I got your unit back, and it works fine. (?)
So, we need to go over a few things to see if we can find out what happened? Please drop me a PM and we can talk.

[Lostboy Steve]

Hey Hondaman, I love the ignition so far. Install was a breeze as well. Would I benefit from dyna 5ohm coils over my factory ones? Do they provide a stronger spark?  Main reason I may change is due to my terrible sparkplug wires. Though they work fine they are highly corroded on the ends and I cant trim them much more. All in all the smallest improvement is a good one.

[HondaMan]

Hey Hondaman, I love the ignition so far. Install was a breeze as well. Would I benefit from dyna 5ohm coils over my factory ones? Do they provide a stronger spark?  Main reason I may change is due to my terrible sparkplug wires. Though they work fine they are highly corroded on the ends and I cant trim them much more. All in all the smallest improvement is a good one.

Well, the 5 ohm coils make a good drop-in replacement. They have a pretty short spark duration, though. You can stretch it a little (like Honda did) by using the 10k ohm sparkplug caps, but this isn't optimum on the 5-ohm coils. I've been working on a good way to solve this situation and have something workable, if expensive. It goes like this:
1. Use the Dyna 3 ohm coils with a Resistor Pack (more on this in a moment).
2. Use the Copper-core spark wires from Dyna for those coils.
3. Find the 10k ohm NGK caps and use those instead of the 5k ohm caps.

#1 above makes an overly-strong, very short-duration spark, not really appreciated in the SOHC4 engine where Honda's coils made 1.2-1.25mS sparks. But, this can be re-tailored somewhat by installing a Resistor Pack to 'slow them down' a little during discharge, and adding the 10k ohm caps will help even more. If you use, for example, the 1-ohm Resistor Pack, it adds about 20% more discharge time (making the 0.9mS discharge more like 1.08mS long), and adding the 10k ohm Resistor Caps (hard to find!) will slow it down another 10%-15%, making it approach the Honda design times. Since the 3-ohm coils generate almost 25kV across a .040" spark gap, and since they will lose about 9kv-10kv to these mods, this leaves it with around 15kV spark potential. This will still readily cross a .035" gap, which will increase the flamefront for the burn (a good thing), and it is almost twice the OEM spark voltage of 7500 volts (7.5kV) that already works fine. These engines, with stock compression, only need about 4kV to actually fire.

But, all I can offer for this "package" at this time is the Resistor Pack. I make them in 1.0 ohm for the 750, and have just started making them in 2.0 ohms for the 500/550 bikes so they have a decent way to get this much-desired, longer spark. Eventually I hope to offer it as a 'kit', if the cost doesn't scare everyone away.

[thirsty 1]

Hey Hondaman,
I read through your post here and would like to try out one of your ignition sets. I'm currently in the middle of rebuilding a 75' 400f. Are these still available? My bike is in pieces and I have a set black 5 ohm Dyna coils on the way. I thought this could be a bit of a cherry on top with the new coils, plug wires, caps, points, and plugs. I'm not in hurry so if it takes a while for the unit that's fine. If you still have them please PM me.
Thanks!

[HondaMan]

Hey Hondaman,
I read through your post here and would like to try out one of your ignition sets. I'm currently in the middle of rebuilding a 75' 400f. Are these still available? My bike is in pieces and I have a set black 5 ohm Dyna coils on the way. I thought this could be a bit of a cherry on top with the new coils, plug wires, caps, points, and plugs. I'm not in hurry so if it takes a while for the unit that's fine. If you still have them please PM me.
Thanks!

I PM'd you back. Just be sure to REALLY CLEAN the cosmolene off those new points, or maybe run them without the box plugged into them for about 100-200 miles or so at first. This burns off the rest of the goo you can barely see, which interrupts the low-current setup from this box. After that, it's fine, and for a LONG time.

[Bowswell]

pm sent hondaman about it to
info@sohc4shop.com

[tbpmusic]

I've had Mark's ignition on my CB450 for three years now, no issues.
Using generic coils from Mike's XS Shop.
In the spring, I check the static timing, then use a strobe to make sure the advancer actually works - then I forget about it until next year.
I went two years without having to reset the timing.

Great stuff, Mark..........

[HondaMan]

I've had Mark's ignition on my CB450 for three years now, no issues.
Using generic coils from Mike's XS Shop.
In the spring, I check the static timing, then use a strobe to make sure the advancer actually works - then I forget about it until next year.
I went two years without having to reset the timing.

Great stuff, Mark..........

Did the timing finally shift, like from points foot wear?
Mine never moved in 7 years, yet.

[tbpmusic]

Did the timing finally shift, like from points foot wear?
Mine never moved in 7 years, yet.

I do believe that's what happened Mark - both sides were a bit retarded (much like the rider), I assume it was from foot wear.
450's have the points on the end of the cam, unlike your Fours, and they get more severe wear as a result (more flexing).

[HondaMan]

Did the timing finally shift, like from points foot wear?
Mine never moved in 7 years, yet.

I do believe that's what happened Mark - both sides were a bit retarded (much like the rider), I assume it was from foot wear.
450's have the points on the end of the cam, unlike your Fours, and they get more severe wear as a result (more flexing).

It's also a lot hotter up there! This usually causes the grease to rub (melt) off the points cam itself, accelerating the foot wear. The CB350 is one of the worst in this regard.

Thanks for the feedback!

[tbpmusic]

Best money I ever spent on a bike........

[billingstitan]

Absolutely thrilled with this upgrade - easy to install - works like a charm. And no more messing with my points!

Took about 20 minutes from start to finish to install this and mount it under my seat. Could not ask for a better quality product for $75 - for those wondering, it's about the size of a pack of cigarettes ... maybe a half inch or so longer.

Awesome product!

[Wnbasac]

wow a lot of reading but just to be sure before i pull the trigger . i've already installed a regulator / rectifier combo into my 500-4 when it was rewired.

so this ignition would be a welcomed addition to my bike to keep her Heart beating that would work along side the reg/rec combo?

tks,lou

[Djfob]

If it was running fine before installing this would only make it that much better.

After my installation I was able to actually kick start my bike. A feat like that was near impossible before.

[c.tran]

Hondaman,

I sent you an email at your sohc shop email

[Hurstman1972]

I need to order a HM transistorized ignition for my '74 CB350F currently being restored, but need a little advice about the rest of the system. What coils are recommended with your system? Plus I intend to replace the old rect/reg units with a  modern Rick's solid state box,. Any concerns there?
http://forums.sohc4.net/index.php?topic=145352.msg1653302#msg1653302

[HondaMan]

I need to order a HM transistorized ignition for my '74 CB350F currently being restored, but need a little advice about the rest of the system. What coils are recommended with your system? Plus I intend to replace the old rect/reg units with a  modern Rick's solid state box,. Any concerns there?
http://forums.sohc4.net/index.php?topic=145352.msg1653302#msg1653302

For the 350F/400F, I'd recommend either the Honda OEM coils from the CB750K0-K6, or (if you can find them) the ones for the 350F. Or, to lighten up the amps load a little bit on these bikes with tiny alternators, you can use the Dyna 5 ohm coils. Also, at Z1 Enterprises, there are some generic coils for the CB750 that will fit (use the ones ending in #-6822) and work fine to over 11,000 RPM.

A "last" alternative, if you're looking for max performance in the 8500+ RPM ranges these Baby Fours will run (make sure your engine is in good shape for this), is to use the Dyna 3 ohm coils with one of my custom-built 2.0 ohm Resistor Packs and 10,000 ohm sparkplug caps, if you can find them.  In this arena, a barely-acceptable second place version is to use the more common 5000 ohm sparkplug caps PLUS the resistor sparkplugs X24ES-U or DR8ES-L, for a total of 7000 ohms. You will find a little bit less performance in the 5000-RPM range, but a little bit of a boost up high in the tradeoff. The reason: the Baby Four spits back into the intake tract (the 350F worse than the 400F) up until 5000-ish RPM, due to the cam and the piston's proximity to the small intake valves. A "hot" spark with rapid rise time (i.e., Dyna 3-ohm coils) will tend to ignite this charge during overlap, which reduces the engine's efficiency in the low midrange (5000 RPM on this engine). Once the intake flow overcomes this burnback phenomenon (around 6500 RPM) the power picks back up. The OEM coils begin to droop (less spark) at about 7500 RPM, where the "modified" Dyna described above will start to perk up a bit.

I first designed this "performance pack" arrangement for the 500/550, but I have not been $olvent enough to package kits of it for our members. I can offer the 2-ohm Resistor Pack, the rest is up to the rider!

[FreeChopper]

Hello! I am trying to contact hondaman. I want to purchase a ignition for my 78 cb750k. And resistors if I need them with dynatek 3ohm coils also.

[HondaMan]

Hello! I am trying to contact hondaman. I want to purchase a ignition for my 78 cb750k. And resistors if I need them with dynatek 3ohm coils also.

Yep, you will need at least the 1-ohm Resistor Pack as well. That is $17, no extra postage if sent with an Ignition.

[ChopSticks]

Hey HondaMan,

Just wondering if these were still available?

and if so did you ever release the ones with teh built in timing light that I read about a few pages back?

If not, I'm horrible with electronics and was just wondering is there any difference from setting the timing via strobe light vs static timing with a multimeter?

I also read somewhere that you shouldn't use the ignition if you have aftermarket coils without the resistor pack, is there anyway I can tel if they are aftermarket or stock? I just got a 1974 CB750. I did purchase an aftermarket ignition switch though since the key was no longer working with the one that came with the bike, does that matter?

Lastly, I received a motogadget m-unit and plan on overhauling the whole electrical system once I've gotten the bike tune properly, are there any conflicts with using the m-unit and your HMI?

[MCRider]

Hello! I am trying to contact hondaman. I want to purchase a ignition for my 78 cb750k. And resistors if I need them with dynatek 3ohm coils also.

Yep, you will need at least the 1-ohm Resistor Pack as well. That is $17, no extra postage if sent with an Ignition.

Mark: I have your transistors. I'm running a set of 35 yo Andrews coils in Orange. I think the Color denotes ohms, I have no idea. Do I need resistors? It seems to be running fine. We've really flogged it, though not a lot of miles, maybe 200.

[HondaMan]

Hello! I am trying to contact hondaman. I want to purchase a ignition for my 78 cb750k. And resistors if I need them with dynatek 3ohm coils also.

Yep, you will need at least the 1-ohm Resistor Pack as well. That is $17, no extra postage if sent with an Ignition.

Mark: I have your transistors. I'm running a set of 35 yo Andrews coils in Orange. I think the Color denotes ohms, I have no idea. Do I need resistors? It seems to be running fine. We've really flogged it, though not a lot of miles, maybe 200.

I think those Andrews coils are 3 ohm, like the Dynas. Adding the Resistor Pack does several things for the bike: first, it reduces some of the excess current usage by those coils (not really needed for the spark, but for 15k+ RPM operation) - this cools off the alternator-regulator system. A second thing: it increases the low-end spark a bit more by slowing down the discharge a little bit longer. If you also add the 10k ohm Resistor Caps to the wires, or at least run the silicone-core wires with resistor sparkplugs with the 5k ohm caps, this will also cool off the coils while increasing the spark burn duration.

The high-output coils all have this in common, whether they be Dyna, ACCEL, Andrews, or some other 3-ohm types: they all have VERY short sparks. This is why the spark looks so "big and blue" to your eye: they discharge all of it, quickly. These engines desire a longer spark, which ignites a wider flamefront, causing a larger, longer burn before the pressures fall below burn level (i.e., this makes for a longer 'power stroke', all else being equal). The fuel never gets 100% burned: it literally flames out when the pressures fall below the level that will support combustion with the remaining oxygen, so making a bigger burn happen at higher compression times is the key.

This is where the longer spark wins. Since the plugs need only 4Kv to start the fire at 0.024" gap, or almost 5Kv at 0.028" gap, even if you open the gaps to 0.050" you won't approach the need for 35Kv like those coils make: more likely around 18Kv will be plenty. Installing resistor plug caps will lengthen the discharge time before this threshold is reached, so the fire remains ON longer. Adding the Resistor Pack to the coil itself drops the top Kv a little bit while improving the full-discharge rate at, say, 12k RPM or less, which both cools off the coil, the charging system, the bike's Keyswitch and Run-Stop switch, all while delivering a more uniform (less "peaky" at 6k RPM) spark voltage.

I hope this doesn't confuse the "Resistor Pack" with the "Resistor Plug Cap" questions, as they can work together on the "hot" coils to adapt them better to these bikes. ALL of the bikes need the Resistor Caps. It is the low-ohm, high-output 3-ohm coils that need the Resistor Packs (IMHO...).