Fuse Box & Coil Power Mod Results

My 77KZ650C1 recently started blowing the main fuse. One time there was evidence of excessive heat on one end of the fuse, and on the fuse box. So I went through the entire electrical system, cleaning each connector and applying dielectric grease. I wasn't completely satisfied that this would fix the problem. So I decided to replace the fuse box with an automotive blade type fuse block. Not my idea. I read about it here first. I also wanted to do Wiredgeorge's coil power mod. I bought the parts to do the coil power mod a while ago, but I wasn't satisfied with the different fuse size used in the inline fuse holder, so I held off on doing this mod. Doing the fuse block mod would solve this problem, so I decided to do both mods at the same time. First I wanted to see how much improvement each change made so I measured voltages before and after. Initially I tried to measure voltages at the battery and at the coils, but the battery voltage drops when you turn on the ignition switch. So instead I decided to measure the voltage drop from the battery positive terminal to the coils, since this measurement is more consistent. With the original fusebox, the voltage drop was 2.0 volts. I don't know if that's bad or not, but it seems like a lot to me. After installing the new fuse block, the voltage drop was 1.35 volts. I didn't expect an improvement of 0.65 volts, especially since I had previously cleaned up the contacts on the original fusebox. I was really surprised to find that the bike ran MUCH better. It seemed to have all the benefits everyone claims for the coil power mod: better cold running, better idle, smoother acceleration, etc. In addition, the blinkers flashed faster. I suspect that the headlight and tailight is brighter too. So, if improving the voltage to the coils by 0.65 makes that much difference, the coil power mod should REALLY make an improvement. After the coil power mod, the voltage drop to the coils was 0.09 volts. OK, this should work great, right? Well, after performing the coil power mod I couldn't really tell any difference in how it ran. If there was a difference it was minor. If I had it to do all over again, I don't know if I'd do the coil power mod, but I'd definately do the fuse block mod. I'm not going to undo the coil power mod, but if anything on it fails, I'll remove it. Having said that, I'm really happy with the way the bike runs now when cold, and how it idles when cold or hot. After doing the coil power mod I forgot to apply choke when I first tried to crank it. It started, but ran poorly. Previously, it wouldn't come close to starting if the choke was off, and even with the choke on, it needed constant adjusting to keep it running until it warmed up a bit. Now, just a little choke and I can pull away smoothly as soon as I want. I'm anxious to see now if my mileage improves.

Getting better power to the coils really improved the way my 650 ran. If you plan on doing the fuse block mod and the coil power mod, I'd suggest just doing the fuse block mod first and seeing how that improves things. If you're still not happy with the results, go ahead and do the coil power mod. If you're not planning on doing the fuse block mod, then I definately recommend doing the coil power mod.

I think I'll change the wiring around a bit so that I can easily switch between the coil power circuit and the oem wiring. This will allow me to easily compare the two, and easily revert back to the oem wiring if the new coil power circuit ever fails.

If you have good soldered connections on the coil mod wiring, about the only thing that can go wrong is the relay contacts burning over time and losing contact. You could wire a toggle switch into that circuit, by wiring one end into the battery power to the relay and the other end into the coil feed from the relay. Then if the relay ever fails, just switch the toggle switch to the on position. This will also help if your battery ever goes dead and you have to push start or use the kick starter if you have one. If the battery is dead it won't kick on the relay anyway, so flipping the switch will bypass it,,
Ride Safe.

Where did you buy the fuse block? I've been looking about, and all the auto parts places around me only carry 4 circuit blocks. My bike has 5 stock circuits.

Myself I did the coil mod , new Dyna coils and new Dyna ignition all at one time and it starts right up, night and day difference. i still have the stock fuse box(next on the list). WhatEVER made the difference, I like it.

Try here for fuse blocks:

www.centechwire.com/catalog/panels/fb4.shtml

if your bike still has the wiring in the bars , pull it out I found a lot of problems with the wires in the bars on my 650

The Milkman wrote:

If you have good soldered connections on the coil mod wiring, about the only thing that can go wrong is the relay contacts burning over time and losing contact. You could wire a toggle switch into that circuit, by wiring one end into the battery power to the relay and the other end into the coil feed from the relay. Then if the relay ever fails, just switch the toggle switch to the on position. This will also help if your battery ever goes dead and you have to push start or use the kick starter if you have one. If the battery is dead it won't kick on the relay anyway, so flipping the switch will bypass it,,
Ride Safe.

I added 7 connections to my wiring. That's 7 additional possible failure points. That's where my concern over failures comes from. I didn't solder the connections, but I think I'll go back and do that. I used some crimp connectors from a kit that included the crimper, so I thought I would get better connections than I did. I'm not satisfied at all with the integrity of the crimps. Good idea on the toggle switch. I didn't even think about a dead battery scenario.

dnpurdy wrote:

Where did you buy the fuse block? I've been looking about, and all the auto parts places around me only carry 4 circuit blocks. My bike has 5 stock circuits.

I used a 4 circuit block. My oem fusebox has 3 circuits.

I have changed mine over to a dyna ignition. With a dead battery I know the relay won't work and it won't start but will it kick start if I install a toggle? Even with a dead battery? Where do I put the toggle?

I installed an aluminum plate under my right side panel to mount my fuse box and relays for the headlight and coils. I had room to mount it there. A thick plastic plate would probably be better though to avoid any chance of one of the contacts shorting out on it. Like I said earlier wire it into the battery power side of the coil relay and the wire going to the coils from the relay. Yes, you can push or kick start it with a dead battery. It takes a good hard kick though.
Ride safe.

Post edited by: The Milkman, at: 2007/06/12 21:56

Post edited by: The Milkman, at: 2007/06/12 21:57