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Jubjub21
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Joined: 30 Mar 2008
Posts: 40
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 Posted: Mon Sep 01, 2008 8:05 pm Post subject: Ah, the sweet taste of success (coil mod) |
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BEAUTIFUL!!
WONDERFUL!!
OUTSTANDING!!
PRODIGIOUS!!
She runs!!!!
What I came to tell everyone though, is about wiredgeorge's coil mod.
If its never been done on your bike...you should do it.
It works extraordinarily well. Before I did it, the idle was erratic and sometimes it would stall below 1500 RPMs. The plugs would always foul and it would run like poo.
But now its like a totally different bike. It idles steady, doesnt stall, the throttle response is worlds faster.
Wow.
If youve never heard of it, heres the link:
http://www.wgcarbs.com/index.php?option=com_content&task=view&id=12&Itemid=26 |
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Biquetoast
MODERATOR
Joined: 04 Mar 2005
Posts: 5287
Location: Green Oak, MI
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| Posted: Mon Sep 01, 2008 8:22 pm Post subject: |
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Amen. Testify, brother.
And HERE are some additional tips regarding that.
Also, once you do the mod, it's a darned good idea to keep a spare relay in your on-board tool kit...
_________________
(1.) '75/'76 KZ400D - Winterized
(2.) '78 KZ750B3 Twin - Winterized
(3.) '78 KZ750B3 Twin - Winterized
(4.) '75 KZ400D - Sold and gone
http://kz750twins.com |
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martijn
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Joined: 15 Aug 2006
Posts: 1072
Location: groningen
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| Posted: Mon Sep 01, 2008 8:48 pm Post subject: |
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so if I'm correct it's just a power transistor with short wires which gives a higher voltage and thus a better spark??
Does it handle a constant 7500 rpm?? or 10.000?? any experience?? |
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Biquetoast
MODERATOR
Joined: 04 Mar 2005
Posts: 5287
Location: Green Oak, MI
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| Posted: Mon Sep 01, 2008 9:01 pm Post subject: |
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| martijn wrote: | so if I'm correct it's just a power transistor with short wires which gives a higher voltage and thus a better spark??
Does it handle a constant 7500 rpm?? or 10.000?? any experience?? |
No, no.... nothing that fancy.
All it does is get "cleaner" power from a fresh wire to the battery, that is triggered from the old wire, via a relay.
It's that "cleaner" power that makes all the difference.
_________________
(1.) '75/'76 KZ400D - Winterized
(2.) '78 KZ750B3 Twin - Winterized
(3.) '78 KZ750B3 Twin - Winterized
(4.) '75 KZ400D - Sold and gone
http://kz750twins.com |
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Jubjub21
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Joined: 30 Mar 2008
Posts: 40
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| Posted: Mon Sep 01, 2008 9:50 pm Post subject: |
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Yup, instead of using an old, worn out wire to power the coil....which may only be supplied with 7-8-9 volts of power because of that old wire, you run a new supply route of power, carrying a full 12 volts to the coil.
More volts the coils have= Better, stronger spark.
Plus along with that good spark, your plugs are running at the correct heat range, which helps them burn ary carbon deposits off and foul less.
How can you lose???? |
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Biquetoast
MODERATOR
Joined: 04 Mar 2005
Posts: 5287
Location: Green Oak, MI
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| Posted: Mon Sep 01, 2008 11:28 pm Post subject: |
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| Jubjub21 wrote: | | ...How can you lose???? |
Yep, all that is true, but it is important to remember that you are introducing another inline point-of-failure.... This is why it's important to use a reputable brand of relay, and keep a spare anyway....
_________________
(1.) '75/'76 KZ400D - Winterized
(2.) '78 KZ750B3 Twin - Winterized
(3.) '78 KZ750B3 Twin - Winterized
(4.) '75 KZ400D - Sold and gone
http://kz750twins.com |
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sledgebone
New member
Joined: 15 Apr 2008
Posts: 9
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| Posted: Tue Sep 02, 2008 1:56 am Post subject: |
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| what years is this mod for? |
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Jubjub21
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Joined: 30 Mar 2008
Posts: 40
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| Posted: Tue Sep 02, 2008 3:20 am Post subject: |
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| Quote: | | what years is this mod for? |
Well, really the mod instruction doesnt specify, but if you think about it, most coils on most bikes have essentially, the same type of power route going to the coils.
All this mod does, is replace the old wiring to the coils with a new circuit.
The reason a new circuit may be needed is because the older a wire gets, the more resistance it gives to electrical flow.
So a coil powered by a 35 year old wire may be getting only 8 volts of power while a coil powered by a 15 minute old wire will get the full 12 volts. |
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DALPILOT
Member
Joined: 21 Jul 2008
Posts: 25
Location: Peachtree City, GA
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| Posted: Thu Sep 04, 2008 2:18 am Post subject: |
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| Biquetoast wrote: | | Jubjub21 wrote: | | ...How can you lose???? |
Yep, all that is true, but it is important to remember that you are introducing another inline point-of-failure.... This is why it's important to use a reputable brand of relay, and keep a spare anyway....
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You don't need the relay! I did the mod about a week ago and it does indeed make a noticeable difference. The coil on the bike (mine is a 1982 KZ440 G1) is not connected to ground, and draws NO current, when the engine is not running. Normally, one end of the coil's primary winding, and the electronic ignition unit are connected to the battery through both the ignition switch and the kill switch. The other end of the primary winding is connected to ground via a transistor in the electronic ignition unit and is switched on and off at a rate determined by the engine rpm. Only when the transistor is turned on during off/on cycling during engine operation is there current drawn from the battery by the coil. You can verify this for yourself by removing the lower wire (red/yellow) from the bottom of the front end of the coil and measuring the resistance from that coil terminal to ground when the engine is off. It won't matter if you have the ignition key on either as long as the engine is off. The resultant, infinite (not really, but huge) resistance reading is proof that no significant current would be drawn even with a direct connection to the battery, when the engine is not running.
The mod, as I have done, it takes advantage of this fact to eliminate the relay: Pull off the red/yellow wire from the bottom terminal on the front end of the coil. Re-connect the coil terminal to a fairly large guage wire (#12 or #14) and connect the other end directly to the positive side of the battery. The easiest place to do that is the HOT side of the starter solenoid. Yes, you should use an inline fuse to protect things in case of a short. That's it, you're done.
When you make this mod, power is supplied directly to the coil without having to pass through the ignition switch, kill switch, connectors, and long thin wires. The kill switch still works the same because the electronic ignition unit still gets its power through the ignition and kill switches. Killing power to the ignition unit, turns off the coil switching transistor, and shuts off current to the coil even though the hot end of the coil is still connected to the battery. The engine immediately shuts down.
I've done this mod to my bike and it works great. It's probably the easiest mod you can make that will really make a noticeable difference. Thanks to whomever first came up with it.
Greg |
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DALPILOT
Member
Joined: 21 Jul 2008
Posts: 25
Location: Peachtree City, GA
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| Posted: Thu Sep 04, 2008 11:18 pm Post subject: |
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Since my last post I've done a little digging into the wiring diagram for some of the earlier models '440s. If your bike has electronic ignition you can ignore this.
However, if your 440 has points you WILL need the relay to do the coil mod. The point and condenser ignition systems may (randomly) leave the points in the closed position when you shut off the engine. If you did a direct wire from coil to battery you would end up draining the battery when that happens.
Greg |
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RVC
Senior Member
Joined: 22 Jan 2008
Posts: 311
Location: Winter Haven, Florida USA
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| Posted: Thu Sep 04, 2008 11:41 pm Post subject: |
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Thanks a bunch there DALPILOT. This is good to know stuff.
RVC
_________________
Rick Van Clief
1981 KZ 440-A2 LTD
1974 Z1-A |
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Biquetoast
MODERATOR
Joined: 04 Mar 2005
Posts: 5287
Location: Green Oak, MI
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| Posted: Thu Sep 04, 2008 11:45 pm Post subject: |
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| DALPILOT wrote: | | .... The point and condenser ignition systems may (randomly) leave the points in the closed position when you shut off the engine. If you did a direct wire from coil to battery you would end up draining the battery when that happens... |
Right. That makes sense. And maybe frying the coil... 
_________________
(1.) '75/'76 KZ400D - Winterized
(2.) '78 KZ750B3 Twin - Winterized
(3.) '78 KZ750B3 Twin - Winterized
(4.) '75 KZ400D - Sold and gone
http://kz750twins.com |
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brown recluse
Senior Member
Joined: 14 Oct 2006
Posts: 81
Location: Georgia, USA
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| Posted: Fri Nov 07, 2008 2:02 am Post subject: |
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| Dalpilot, got a quick question, when you mention an inline fuse, what capacity fuse is advisable? |
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thxone
Senior Member
Joined: 25 Apr 2008
Posts: 917
Location: Saint Marys Georgia
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| Posted: Fri Nov 07, 2008 4:52 am Post subject: |
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Well then....I just happen to have some crimp on ring terminals and some 12awg Oxygen free Stinger speaker wire that I used to pound the piss out of some Rockford Fosgate ten inch subs...I may just go ahead and do this mod when the sun shows itself again....then again I have some 4awg amplifier power wire but that may be to big to route to the coil. Keep them ideas coming.
_________________
'82 KZ440 LTD A3
Averaging 50mpg!! |
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JSDiamond
Senior Member
Joined: 19 Jul 2008
Posts: 68
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| Posted: Fri Nov 07, 2008 6:02 pm Post subject: |
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| Quote: | | Right. That makes sense. And maybe frying the coil... |
Bique is right on, and I can personally attest that absolutely will happen on a points bike. It happened on my ironhead sportster. It drains the battery and your coil will roast until the seams split and the oil paste leaks out. You need the relay or a kill switch (an on/off toggle, not an interrupt).
My bike does not have points, so I did the coil mod by simply placing a kill switch inline with my key switch. Turn the key off and/or toggle the switch off, no power leaks. But both have to be on for power to the bike and for the 'mod' to be working. It works great. I also recommend a pair of new solid copper-core plug wires from Accel or another reputable company to give your plugs a clean and quick spark. |
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