i know im late to the topic but i have a few questions about the set up that i was planing on running.
its a 76 cb750f
bought a dyna 2000 and 2.2 coils and suppression wires.
from what im reading now this will not work all that well with out resisors? or is that just with the dyan s?
also the goal as im sure others is to have better and more contolled spark.
i had already thought about the power draw of the dyna 2K and thought running LED lights and such could help save some power for charging the battery and also to buy a battery with more amp hours then stock.
im not very good with elcetronics but im learning. its nice to see that there are people out there that have the knowlage and are willing to help others
thanks
First, it's important to understand that using a battery with more amp-hours won't help anything, here. The battery is just a "bucket", holding onto electrical current, and if there isn't enough to go around, there also won't be enough to store, either. Keep that in mind, and use the money elsewhere in your project. A standard battery will be fine.
I don't know all the INs and OUTs of the the Dyna 2000. But, here's the things you need to know about your bike to use that gizmo:
1. Honda has designed for up to 3.2 amps total ignition current in the old CB750 system. So, you must either give up some current elsewhere if your ignition is going to use more than that. An LED taillight will save an average of 0.2 amp, not all that much extra, there. The standard headlight is 50w/60w, and all halogens are more than that: you may have to switch to an older sealed-beam headlight to get it into the 45 watt range to save power there.
2. The wires that feed the coils from Honda's wiring harness are not heavy enough to run those 2.2 ohm coils for long. The wires will heat, and the insulation crack, and the splices (that feed other circuits) will begin to overheat and fail over a year's time or so. This will cause all sorts of other problems to appear, like with turn signals, handlebar switches, and the like. So, you must run separate wiring for the coils: run a 20 AWG wire from the IGN fuse up to the headlight, leaving the original wire in place, and join (or splice) it into the original wire inside the headlight, which will connect into the handlebars' KILL switch. This wire will help shunt the extra current needed by the new system, lowering the losses and heating elsewhere.
3. Using resistors will help: I currently have 1.0 ohm units for 3-ohm coils, and 2.5 ohm units for the riders using the 2.0 ohm Gold Wing coils. The 2.2 ohm coils should use 2.0 ohm resistors to directly match Honda's original specs. If you wanted them, I could probably make up a set like that, for a few extra bucks.
4. Consider the tuning capability of the Dyna 2000: if it has adjustable dwell, set it high, like a points ignition (180 mechanical degrees, or 90 electrical degrees (which shows up as 45 degrees on a dwell meter). Don't set it low, like a Dyna "S", or you will definitely have overcurrent problems.
