Honda Twins banner

1 - 20 of 41 Posts

·
Registered
Joined
·
124 Posts
Discussion Starter #1 (Edited)
So the back story is that I develop multi-spark optical ignition systems for vintage bikes and cars.
I've been working with the developer of the electronics for a while now on the Honda twins, he's come up with a solution that I think will work out great.
The unit is a hybrid of the mini-coil we use on other bikes like the KZ twins and the bigger inline 4's
It has all the electronics built into an 80k volt coil, it uses the stock points or magnetic pickups from other systems the condensers are also not needed. It simply uses the points as a trigger, with only a few mili-volts passing thru them. The electronics handle everything else. We also use standard automotive 8mm resistor core wires.
The unit is just under 4" long and 2" wide.

I'll be installing the new unit on my daughters CL build and I'll post pics of the coil mount and how it runs when it happens.

Here are some images of the unit.
 

Attachments

·
Registered
Joined
·
4,458 Posts
Nice. Can't wait to see the test results.
 

·
Premium Member
Joined
·
24,208 Posts
Very interesting. Is this similar to a CDI system where the coil is dead until a power pulse is sent? That would solve the low voltage ignition failure prevalent to the 350's since there'd be minimal voltage draw.
 

·
Registered
Joined
·
124 Posts
Discussion Starter #5
Very interesting. Is this similar to a CDI system where the coil is dead until a power pulse is sent? That would solve the low voltage ignition failure prevalent to the 350's since there'd be minimal voltage draw.
The systems will be similar. Our normal system shuts the coils down when there is no crank/cam movement. Our coils can fire at full power with as little as 10.5vdc input.
 

·
Premium Member
Joined
·
10,203 Posts
Nice to see. Any thoughts on how it could be used on the wasted spark CDI systems on our SOHC bikes?
 

·
Registered
Joined
·
124 Posts
Discussion Starter #7
Nice to see. Any thoughts on how it could be used on the wasted spark CDI systems on our SOHC bikes?
I have a wasted spark system already for the SOHC 4's
I have put systems on KZ twins, KZ/GS/CB inline 4's, HD twins, H1 & H2's, water buffaloes and GT's - I can do from 1 to 12 cylinder 4-stroke and 2 stroke engines.
Our coils are designed to function with our ignitions systems, once my testing is done, we'll look at other options.
 

·
Registered
Joined
·
124 Posts
Discussion Starter #8
Worked on the mount today for the new coil, a simple piece of aluminum angle with a notch cut out on the mill.
I wanted the bracket to simply attach to the stock bracket so there would be need to modify the stock one.
 

Attachments

·
Premium Member
Joined
·
24,208 Posts
OK, I was envisioning that this was 2 coils like stock. Where do the plug wires come out, side and front?
 

·
Registered
Joined
·
124 Posts
Discussion Starter #10
OK, I was envisioning that this was 2 coils like stock. Where do the plug wires come out, side and front?
Have a look at the images in the first post, one plug wire comes out the top and the other out the side.

This is a single coil design.
 

·
Premium Member
Joined
·
24,208 Posts
OK, that's what I was seeing but wasn't sure if that was correct. When do you envision these being available?
 

·
Registered
Joined
·
124 Posts
Discussion Starter #12
OK, that's what I was seeing but wasn't sure if that was correct. When do you envision these being available?
I'll do some testing first for documentation, that should take about a month to collect the data and make any changes needed.
I'll put together a kit that will include the coil, bracket, coil wires and hardware. It's a simple 3 wire termination that will plug into the stock wiring harness with no modifications and will bolt directly to the stock coil bracket, again with no modifications.

I'll be working on the price of the kit this week and if all goes as expected I should be able to start shipping the middle of January, I'll post the kit price when I'm ready to start shipping.
 
  • Like
Reactions: slofut

·
Super Moderator
Joined
·
5,926 Posts
The CL350 has 2 sets of points. How is a single coil going to work? The 350 does not use (with stock ignition points) a waste spark method (single coil). So to use a single coil, you would need to change the points cam to accommodate a single pojnt system with waste spark. That's pretty complex. There are electronic systems that use waste spark on the 350/360 ignition, but that system replaces the points cam entirely. The later CB-CM400 etc already use a single coil system, tso your new coil would work with that, but this single coil is a lot more than a bolt on solution for the 180 degree CB350 and 360 bikes and others that are not single point per 2 cylinder. The 4 cylinder bikes generally have a waste spark, single coil to 2 plugs, but the 350/360 twins do not.
 

·
Registered
Joined
·
13,085 Posts
The CL350 has 2 sets of points. How is a single coil going to work? The 350 does not use (with stock ignition points) a waste spark method (single coil). So to use a single coil, you would need to change the points cam to accommodate a single pojnt system with waste spark. That's pretty complex. There are electronic systems that use waste spark on the 350/360 ignition, but that system replaces the point can entirely. The later CB-CM400 etc already use a single coil system, tso your new coil would work with that, but this single coil is a lot more than a bolt on solution for the 180 degree CB350 and 360 bikes and others that are not single point per 2 cylinder. The 4 cylinder bikes generally have a waste spark, single coil to 2 plugs, but the 350/360 twins do not.
I'm looking forward to that answer as well, along with the price, based on the 80k volt output that would be beneficial for my 450. I get the feeling he has separated the coil sections inside the unit and the 3 wire input is one for power and the other 2 for each points connection
 

·
Registered
Joined
·
124 Posts
Discussion Starter #15
The coil is not separated internally, it has +/-12v input and the single trigger input.
The electronics are designed to react to the 2 separate inputs from the points on the single input to the coil, this along with the extremly fast dwell will fire each plug at full power in the correct cycle of the engine. Our coils can fire at full power with as little as 10.5v input.

I'm going to button up a few things on the engine today and see if get it started.
I'll post pics and a video if I get everything accomplished today.
 

·
Registered
Joined
·
13,085 Posts
The coil is not separated internally, it has +/-12v input and the single trigger input.
The electronics are designed to react to the 2 separate inputs from the points on the single input to the coil, this along with the extremly fast dwell will fire each plug at full power in the correct cycle of the engine.
So in the case of a 180° twin like 350s and 450s, do you have to diode the points apart?
 

·
Registered
Joined
·
124 Posts
Discussion Starter #18

·
Registered
Joined
·
124 Posts
Discussion Starter #20
So both wires from both sets of points are connected to a single trigger lead?
Correct.
I put the starter back together last nite, I'm going to try and start the bike this weekend.
 
1 - 20 of 41 Posts
Top