testy

Author Topic: Transistorized Ignitions, aka Hondaman Ignition in Dual, Single, and now Triple!  (Read 73403 times)

0 Members and 1 Guest are viewing this topic.

Offline ChopSticks

  • Hot Shot
  • ***
  • Posts: 450
Re: Transistorized Ignitions, aka Hondaman Ignition...and Gas Cap Hinge Pins.
« Reply #175 on: February 11, 2016, 02:18:34 pm »
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 (just discovered it has a '78 F3 engine in it). 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?

Also I noticed a resister option available if you have a 3ohm set up, what's the reason to go to a 3 ohm instead of keeping the stock 5ohm ignition coils?

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
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 (just discovered it has a '78 F3 engine in it). 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?

Also I noticed a resister option available if you have a 3ohm set up, what's the reason to go to a 3 ohm instead of keeping the stock 5ohm ignition coils?

There are many riders who believe a "hotter" spark is better than a "stock" spark. Dyna started making these high-output coils back in the era when cars used points and often had barely enough spark voltage (GM cars, in particular) to make them run. When their points burned, the voltage fell off rapidly. Companies like ACCEL, Borg-Warner, and Jacobs started making higher-voltage coils in those days (1960s-1980s era) which made those cars run better, especially in cold weather. This bred a "common knowledge" sense among fledgling wrenches that "hotter" sparks were somehow "better" in all engines, and in the raging days of the 1960s-1970s era, kids my age "distrusted the establishment" in any form, including big business. Over time, this created a mindset that anything "stock" from any big company was made as cheaply as possible, so ANYTHING aftermarket, especially if it was expensive, must be better.   Right?

This mindset still hangs around, although it survives largely by word-of-mouth over beers (or similar diversions). Honda, in the case of the SOHC4 bike, did a stellar (in 1970s tech) job of matching the spark duration to the long-stroke 750 engine, a design feature they learned from their own CVCC car engine of the same decade. It only takes about 4000 volts to fire these engines, and the coil voltage was set at 7500 volts to survive poor gas and maintenance, fouled plugs, or somewhat-worn parts, like plug caps (which have resistors inside). This allowed lots of margin. More importantly, they set the inductance of the coil high enough that the spark lasted an amazingly long 1.5mS, where most cars (and earlier Honda bikes) had sub-1mS spark duration. This was done because, especially in the CVCC and SOHC4 bike engines, the air-fuel charge enters the cylinder at a sharp angle, then spins to almost 700 MPH during the compression stroke in a whirlwind pattern (on purpose). The reason: this pushes the fuel molecules toward the outside of the chamber and makes the center leaner: when the spark lights it  the richer portion lights easily, and as it burns and heats up it later starts off the leaner center portion. This 1-2 step burn extends the length of time the fuel burns, making it push longer on the piston. The undersquare SOHC4 750 (and 350F) engine design amplifies this even more, allowing a much wider powerband with the 187cc piston than would otherwise be possible. Honda was apparently concerned that while the Four could spin faster than any competitor of the day (9k RPM, easily) and make lots of HP at those speeds, it should also have good low-end torque for around-town riding. A long spark thus improves the low-end torque noticeably.

In cars of the old type, with points, Jacobs could bring out 10HP more on a 350 cubic inch engine, for just installing their coils: they tripled the typical spark duration by using heavy iron (and lots of it) cores and low wiring impedance, but with more resistance in the ballast resistor (aka "Resistor Pack", here) than OEMs did, and by using resistor wires and plugs where OEMs then used either one or the other of these items.

So...applying these techniques to the SOHC4 bikes: Honda used a long iron core (150mm+ length) and very fine secondary wires, superbly wound, to pack extra inductance into the 750's new coils. Then they installed 7500 ohms in the plug caps, to slow down the discharge time even more. The result was terrific! The spark does not droop more than 7% from 100 RPM to 11000 RPM when the parts are all new. But, the resistor caps don't last forever, nor do the rubber sleeves of the coils: such was the 1970s tech in Japan! In the case of the "F" bikes, Honda needed more top-end spark, as the primary drive ratio was lowered in these engines, making them spin about 800 RPM more than the early engines at equivalent hiway speeds. The carbs were also set leaner (to meet new EPA regulations at the time) and this required more spark voltage ("hotter") to start it reliably when cold. This led to the post-1975 coils with shorter spark duration, but 800 volts more spark, so they used 10,000 ohm sparkplug caps to try to stretch it a little more: these caps quickly burned out.

...that's where the problem started. Within typically 8k-10k miles, the plug caps were burned past their limits, but no one seemed to know they should change them: instead, the popular "fix" became the old adage again, "...use a 'hotter' spark, because it is 'better'...". Dyna offered their 3-ohm, high-output coils in those days, and simply plunking them into a bike with bad plug caps would make them run (especially when cold) better...for a while.

Oddly, today this whole mindset persists, despite hundreds of articles, books, kits, and other things that prove it wrong. Old habits die hard? At any rate, just keep this in mind: a LONGER spark will make any engine run better, which is why the multi-spark ignition systems are standard fare on any race vehicle now (and many EFI cars today!). So, go for the LONGER duration spark, not a HOTTER one: in any physical size of coil, only a certain amount of spark energy can be made. If it discharges quickly, the voltage is higher: if it discharges slower, the duration is longer instead. And, even at 10:1 compression ratio, it still only takes 6kV to fire these engines at 10k RPM, so even the OEM coils will make plenty of voltage.

So, IMHO the final answer to the question: "Why 3 ohms instead of 5 ohms" is: that's the wrong direction!
« Last Edit: May 16, 2016, 11:13:45 am by HondaMan »
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline ChopSticks

  • Hot Shot
  • ***
  • Posts: 450
Great! Definitely will stick with the stock set up then, just was making sure in case I needed to order one with resistors.

Also do you know if there are any conflicts with setting the HMI up with a motogadget M-unit?

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Great! Definitely will stick with the stock set up then, just was making sure in case I needed to order one with resistors.

Also do you know if there are any conflicts with setting the HMI up with a motogadget M-unit?

I wouldn't think so: my Ignition unit is free of interference against things like AM radios, etc., so I doubt it will cause any other electronic issues.
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline jodangler

  • Full Member
  • *
  • Posts: 16
I just had an issue yesterday with my cb750k7, she just quit on me, she started up again after 10min but it sounded weak so I shut it down and left her in the parking lot. I went back in the afternoon and started her up and she sounded like her old self again. Im wondering if coils are getting hot and just quit, im also wondering if your ignition system will fix this???     

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
I just had an issue yesterday with my cb750k7, she just quit on me, she started up again after 10min but it sounded weak so I shut it down and left her in the parking lot. I went back in the afternoon and started her up and she sounded like her old self again. Im wondering if coils are getting hot and just quit, im also wondering if your ignition system will fix this???     

Well, the ignition box won't fix an ailing system. First, you must figure out what is causing that problem. It will still be there if you just add this box. Often, the condensors can act like this, or [real] bad coils can cause it, or it might be a fuel-feed trouble of some sort? Maybe make up a post in the SOHC4 Bikes section and report your findings and symptoms: there's lot of people there who can see it and help. ;)
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline BrynrG

  • Full Member
  • *
  • Posts: 9
Haven't seen much (read so long the letters are blurring) on anyone using these on their 1979 CB650. I think I'd like to add
this HMI. Just want to make sure there isn't something "special" about the 650's I don't know about.

-JBG

Offline RAF122S

  • I feel like a
  • Really Old Timer ...
  • *******
  • Posts: 7,120
  • SOHC 4 member # 2605
BrynrG,  I don't think the 650 used points did it?  I thought it had Electronic pickup coils and little black boxes that drove the coils... I forget what the boxes were called.  Ignitors?  I believe it was a CDI ignition system, rather than points based.
There were some folks looking at talking Pamco into designing one of his electronic ignitions to fit the 650.

David
David stuck in the curvy back roads of "Upper East" TN

Offline BrynrG

  • Full Member
  • *
  • Posts: 9
You know I descovered you're exactly right. After reading and reading I just said screw it and went and took the thing apart cleaned it up (little rust) and she started right up! Now to clean the carbs!
-Brynr

Offline Pan1cReaper

  • Enthusiast
  • **
  • Posts: 112
Ive had enough of dick chang cheap condensers failing in me. Can I still order one of the basic units? What is your preffered method of payment?

Offline stikman

  • Bit of an
  • Enthusiast
  • **
  • Posts: 190
I completed my first season with Hondaman's Transistorized Ignition installed.  No issues.  Installation was easy.  Thanks again, Mark!
1977 CB750A "High Horse": 836cc, mild porting, custom cam, K5 roundtops, v-stacks...
1973 CB750K D5 plunger frame chopper currently building..

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Ive had enough of dick chang cheap condensers failing in me. Can I still order one of the basic units? What is your preffered method of payment?
Sorry I didn't see this earlier: are you in the US, or outside?
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline auro

  • Enthusiast
  • **
  • Posts: 116
    • photostream
...and it's now on my 350F as well.

still positively surprised by how painless the setup has been, literally followed the instructions and it worked 1st time.

amazed.

thank you mark!
CB350F (1975)

Offline StevenL

  • New Member
  • Posts: 1
Hi, If the Ignition system is still available I would like to get one. Also I have a 6 volt Honda XL100. Is it possible to convert it as well?

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Hi, If the Ignition system is still available I would like to get one. Also I have a 6 volt Honda XL100. Is it possible to convert it as well?
I still make them: do you want a dual-channel type for the SOHC4, or just the XL100? If for the XL, does that one have points in it? I do make a Single version for those bikes (like the CA95, CB100/125, CB175, etc. that have one set of points at 6 volts). Drop me a line at HMAN750@gmail.com if you want the nitty-gritty details of them. Where do you live?
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline jonho888

  • New Member
  • Posts: 1
Will it be possible to order one for my 550 (1976) with the security switch. My bike is stock standard. I am in Auckland, New Zealand. Can I do a bank transfer to your account? Thank you and kind regards.

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Will it be possible to order one for my 550 (1976) with the security switch. My bike is stock standard. I am in Auckland, New Zealand. Can I do a bank transfer to your account? Thank you and kind regards.
Hi, Jonho! Sure, PM me for details.
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline theriddler

  • Full Member
  • *
  • Posts: 41
  • 1976 CB750F1
Hi - hopefully these are still available, as I'd like to order one for my CB750F1.... only problem is I live in the UK?
Just getting back into my bike after a year or 2 out & thought this would be a good upgrade (as opposed to electronic ignition)?
By the way, one of the thing that has kept my interest going through difficult times has been reading the book "My CB750 Book".... I think it is your book??? Anyway - a great inspirational book (along with my bible...)!!
Regards - John

Offline theriddler

  • Full Member
  • *
  • Posts: 41
  • 1976 CB750F1
Sorry ... by electronic I mean pointless ignition system...

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Hi - hopefully these are still available, as I'd like to order one for my CB750F1.... only problem is I live in the UK?
Just getting back into my bike after a year or 2 out & thought this would be a good upgrade (as opposed to electronic ignition)?
By the way, one of the thing that has kept my interest going through difficult times has been reading the book "My CB750 Book".... I think it is your book??? Anyway - a great inspirational book (along with my bible...)!!
Regards - John

Now you're talkin' about BOTH of my favorite books! :D
Drop me an e-mail at hman750@gmail.com. I have a special deal going for UK riders (when it is available). I'll explain there when I get your e-mail.
;)
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline theriddler

  • Full Member
  • *
  • Posts: 41
  • 1976 CB750F1
Email sent ...

Offline grcamna2

  • Not a
  • Really Old Timer ...
  • *******
  • Posts: 7,333
  • I love to restore & travel. Keep'em Going Strong !
Thank you Mark for still offering these quality ignition boxes to us here.I really enjoy the one I purchased from you and hope you are able to fabricate/manufacture 5-wire and 6-wire R/R units that will be made w/ the same quality you use to make these great ignition boxes.You have the best quality/control and prices anywhere.  ;)
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S',1982' Suz. GS450TXZ
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 9,485
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Thank you Mark for still offering these quality ignition boxes to us here.I really enjoy the one I purchased from you and hope you are able to fabricate/manufacture 5-wire and 6-wire R/R units that will be made w/ the same quality you use to make these great ignition boxes.You have the best quality/control and prices anywhere.  ;)

Thanks for the kudos!
I hope it gets more of these bikes back on the road, and for longer. :)
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: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 8,166
  • Bike almost back to the 70's 2015
Mark, do you recommend a specific pair of coils to your ignition?  Cheaper and better than Dyna would be fine ;)
To CB750 K2 mostly, bigger bore with higher CR, ported head, cam like RC295, MIKUNI VM29 smoothbore.
I guess an OEM 736 Honda will have same need.

I have currently Dyna 5 ohm coils in my modified K6 together with your ignition.
One weak point is the auto type ign wire connection in the Dyna coil, it can move out and cause intermittent functionality. Need to add a "wire holder" very close to the coils outputs.

- Complete package, ign module and coils?
CB750 K6-76 1005cc JMR Billet block.
CB750 K2-75 Parts assembled to stock K2

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 8,166
  • Bike almost back to the 70's 2015
Subscribed
I could not modify my previous post.
CB750 K6-76 1005cc JMR Billet block.
CB750 K2-75 Parts assembled to stock K2

 

;