Topic: What are all the cool kids using for electronic ignition these days? '70 CB750K

[PeWe]

My K6 had full advance before 2000rpm. This with Pamco ignition. Totally impossible to get it running evenly. Then with CX-7 cam. (Close to Megacycle 125-75)

Thanks to Hondaman's written thoughts and other forum members experiences I could fix it by cutting the springs.
After that fix full advance at around 2600 rpm, maybe a little later, but not after 2700rpm. That is explained in the old thread when I had that problem late 2013.

After Pamco I used TEC points with Hondaman unit and Dyna-S since dyno runs indicated eventually bouncing points after 8000 rpm.

An engine with hotter cam get more stable idle this way holding the advance.
Also a stock.
This is visible with timing lamp, marks will be seen as stable, not jumping around.

My K2 that is almost fully stock except for Cruzinimage +0.50mm K7 pistons, K7 cam and Yamiya no numbers 4-4.
I could not get the TEC ignition to retard enough so F lined up with case mark. Plate max clockwise.
It was an irritating mm or 2 advanced. I tried with points at max gap.

I cut the springs and it lined up exact at full clockwise position.
Also that bike got later a Dyna-S.
With Dyna-S no problem with ignition plate not enough clockwise.
It work fine in the middle to start with, fine tune with timing lamp at idle.

My K6 original advancer springs were really sloppy. I could rotate cam several degrees until springs hold it back.
Better when springs hold the cam from the first degree.

My K6 that has been rather modified, now with 970cc, ported head, Megacycle 125-75 cam and very responsive Mikuni TMR32 flatslide carbs runs very evenly when carbs are properly jetted.
The nice idle and relatively smooth rpm increase at take offs should not be possible with too early advance.

That cam is often seen as rather hot but behaves good with stable idle at 1200rpm. 1000rpm is possible but the rather high compression make it to run rather hard, 1200rpm work better.

I prefer 1200rpm on my almost stock K2 too. Easier at take offs, ensure oil pressure too.
I doubt that a Dyna 2000 with 4 different advance curves without advancer unit should make anything better.

Stock advancer with cut springs deliver what needed.
I have it documented on Dyno charts

The racer guys should save money using Dyna-S with stock advancer with cut springs instead of buying the more expensive Dyna 2000 avoiding the advancer.

Cut springs will not harm the engine, only doing better.
If cutting one loop on one side of a spring, the loop that is attached to something.  Bend out the outer end and a new loop is made. Form it with 2 pliers and hook it in place.

[Deltarider]

I just try to establish whether 'sloppy springs' is a genuine CB500/550 issue or one that has been transferred from an issue the CB750 may have had. Such a transfer has happened before, when the central bolt on a CB500/550 ignition, the one which fastens the advancer (#15 in the pic), was said to become bent causing a possible misalignment. I have never seen one which had that problem. Not on a CB500/550 that is. I know that on the CB750 this central bolt could cause a problem.   

[greenjeans]

ive run the boyer units trouble free on a few bikes,its one of those things?ive heard of plenty of dyna failures but how much is installer error?some guys cant even get a headlight to work and at the same time install electronic ignition etc and its all the products fault?i never chime in on electricals because i HAVE to see it first hand.

Ah, somehow I forgot about Boyer.  I have one on my '70 Tiger 650.   I do love that it eliminated the advance.   I think this may be the winner.

I second the use of Boyer Ignitions.  I installed and sold many of them on British bikes, when I worked at a shop, and I've never seen one fail.  My personal Norton Commando has had one installed since the late 70s.  The nice thing about a Boyer ignition is that it eliminates the mechanical advance. 

[Scootch]

Would you guys please elaborate on the Boyer units. I'd like to know more about them and their design.

[seanbarney41]

Hondaman on one of my bikes for years now.  Absolutely no point adjustment needed for last 20k miles or so (no odometer on bike)  I have checked and lubed the points cam...not even once a year.

[bryanj]

Family firm in UK started with units for triumphs, nortons and bsa, very good reputation forreliability and backup. Never known a unit fail but personaly not keen on firing all coils at one.
I once ran for a fault finding chart/process and arrived within hours with honest comment that they have never had one back unless physically damaged or wired wrong

[Bailgang]

but personaly not keen on firing all coils at one.

Yeah but there is some sort of "voodoo" electronics going on that I can't explain. I've got a boyer on my 750 and noticed right away when wiring up the coils that they were wired in series which I thought was odd. I mean you have a wire from both the 1 and 4 pickup and another one from the 2 and 3 pickup, both going into the unit but only 1 wire for the negative side of the coil coming out so you would naturally think both coils fire at the same time essentially giving you a double wasted spark but this is where it gets weird because my timing light doesn't see it. What I mean is that if I have my timing light on the 1 or 4 wire, my timing light will only see the 1 and 4 mark on the advance. You would think that with the coils wired in series that I should randomly see the 2 and 3 mark as well but I don't. If I want to see the 2 and 3 mark I have to put the inductive lead of my timing light on a 2 or 3 plug wire and even then I will only see the 2 and 3 timing mark. So my question to all of you boyer users is if both coils fires at the same time (being how they're wired you'd think they would) then how come my timing light doesn't see it? Is it just me? Do I need a new timing light? To all you boyer users, put your timing light on and check for yourself and let me know what you see because I sure would like to know.

For those of you interested in a boyer bransden ignition, please note that they will not work with an external rev limiter, it actually has one built in but if you buy one from a dealer/seller, that built in rev limiter isn't activated nor can it be once the "brain box" has been made. If you want your boyer with a rev limiter, you have to contact boyer directly and specify what rpm limit you want and they will program that as they make it. I thought I had issues with mine and sent it back to them and figured while they had it that maybe they could program the rev limiter. They told me they couldn't, they can only do that as they are making it. They offered me a sweet deal on a new unit with the rev limiter set at my desired rpm but I passed because I didn't have the spare funds. The problem I thought I was having with the boyer turned out to be my fault. One of my soldered connectors broke but I couldn't see it because of the heat shrink I had on it and the unit was actually fine.

[C317414]

Would you guys please elaborate on the Boyer units. I'd like to know more about them and their design.

Boyer has two distributors in the US:  Coventry Spares, and JRC Engineering.  Both specialize in spares for classic and vintage British bikes, and neither sell retail.  JRC recently started stocking Boyer ignitions for Honda fours.  Look for a shop that deals in classic British bikes, and ask them to order the ignition from JRC.

[dave500]

on the boyer bailgang with the timing light,if you look close the 1/4 and 2/3 marks sort of ghost as it flashes,at least mine does,i like them,if i didnt have boyer id be happy to use those cheap units you see kokurin or something?when setting up the boyer timing,just increase the rpm with a timing light and watch it advance till it stops,then just set the plate where you want the full advance to be,i go just a touch past that second hash mark,where the f mark is at idle dont worry about it.

[Old Scrambler]

I had a Dyna-S on my race bike with no problems. Now learning to install an Ignetech unit which is similar to a Dyna-2000 but about $100 less and considered more reliable. My unit has a black-box so I will be able to set a rev-limiter and use ignition-retard maps for high RPM performance. They did not send the correct signal disk so now waiting for a replacement.

[Bailgang]

on the boyer bailgang with the timing light,if you look close the 1/4 and 2/3 marks sort of ghost as it flashes,at least mine does,i like them,if i didnt have boyer id be happy to use those cheap units you see kokurin or something?when setting up the boyer timing,just increase the rpm with a timing light and watch it advance till it stops,then just set the plate where you want the full advance to be,i go just a touch past that second hash mark,where the f mark is at idle dont worry about it.

I definitely need a new timing light, the one I have doesn't work well on any of my bikes.

[PeWe]

on the boyer bailgang with the timing light,if you look close the 1/4 and 2/3 marks sort of ghost as it flashes,at least mine does,i like them,if i didnt have boyer id be happy to use those cheap units you see kokurin or something?when setting up the boyer timing,just increase the rpm with a timing light and watch it advance till it stops,then just set the plate where you want the full advance to be,i go just a touch past that second hash mark,where the f mark is at idle dont worry about it.

I definitely need a new timing light, the one I have doesn't work well on any of my bikes.

Tried to use a separate battery? Not the battery on bike you check the timing.

I use an old motorcycle battery, good enough for timing light.

Battery on floor beside ignition makes it easier too

[Bailgang]

Tried to use a separate battery? Not the battery on bike you check the timing.

I use an old motorcycle battery, good enough for timing light.

Battery on floor beside ignition makes it easier too

I just recently read about using a separate battery when using a timing light on a motorcycle, I just haven't tried it yet. I would still like to compare my timing light to another one, preferably one that doesn't have an advance function just to make sure the one I currently have is accurate. Mine does have an advance feature and I just want to make sure it's still working properly being it's at least 30 years old. Years ago I was with my nephew at a drag strip and his car was pinging like crazy and he had to back off his timing a bunch until it stopped. Considering the comp ratio of the engine and fuel it was using, it should've been just fine with the total advance he had initially set it at but he had to back off timing at least 10 degrees to get the engine to behave. That didn't make sense to me so I told him he should try another timing light to confirm his timing light was ok. My nephew blew my suggestion off saying it was a Mac Tool timing light that cost him $300 so it had to be accurate ..... uhm no it wasn't but he didn't find that out until a few days later when he finally did try another timing light.