Quick help please, no tacho, lost a cyl or two

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Catalin24
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My Bike: ZXR 400 L5

Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Wed May 01, 2019 6:04 pm

So recently my bike had a major short in it loom and i've lost: the parking lights, the tail, the tacho, and a cylinder or two(my guess two, my ear isnt that fine). Found the major mess and redone the wiring in that spot, the tail came back fully, parking lights but the tacho is dead and the bike runs on 2 or 3 cyl. Im looking on the wiring diagram for a few hours and i dont really know how to test what wire/s are bad. With my multimeter i've tested the tacho conector and all wires we're shorted to BR/W (except Y/W form water temp gauge). I've read on the form that the tacho might get power from the 1&4 coil, my thought: Maybe there is no power geting to that coil so the tacho doesnt work either?

How and what should I check? Thanks !

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Miles
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Re: Quick help please, no tacho, lost a cyl or two

Post by Miles » Wed May 01, 2019 10:49 pm

If the bike is able to run then I would see what voltage is getting sent to 1/4 coil.

Banner would be the man to ask though, he’s quite well versed in the electrical issues on these bikes.

Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Thu May 02, 2019 12:56 pm

I've made some checks: both coils get 12.50V when i crank the engine(drops fast to 10.5V though then the engine is rotating). I dont get spark to cyl 1 and 4, and the coil gets hot in compared to the second coil (2 and 3). I get spark on 2 and 3.
The internal resistance of the coil 1 and 4 raise up(i believe over the specifications) Primary: 3,6-7 Ohm, Secondary: 25,1kOhm. Coil 2 and 3 is still at 3,2Ohm primary (like last year). The brown wire and black(signal for tacho and coil) shorted in the fire. (along others)

BR/W and BK are shorting when i put the kill switch in the run position. (i dont know if thats right or not)
I get 12.5V from R/BL - BR/W , BK/Y-BR/W , Y/W-BR/W

Bad coil (1and4) ? Bad CDI? Shorts on the tacho connector? (visually i didnt saw anything)
banner001 Help me again brother, i need your brain. :smt017

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banner001
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Re: Quick help please, no tacho, lost a cyl or two

Post by banner001 » Thu May 02, 2019 4:30 pm

#Ok, so first thing to do is swap the power leads on coil 1 and coil 2 over and check for sparks, this will ensure that both coils are functional.

#Coils have a constant electricity feed down the red wire, the other wire is grounded by the CDi and this causes the coil to fire, so you should have ~12.6V at rest on each red wire to ground.

#If these two tests show that you have power to each coil, and that you are still only getting sparks out of coil 2+3 then you must have a break in the black wire from coil 1+4 to CDi, or the CDi is faulty.

#The black/yellow and brown/white wires to tacho, these are the ground return and power feed respectively, the tacho pulse feed is the black wire grounding through the CDi. I dont know what you mean by "shorting" when talking about the brows/white and black wire on the tacho, do you mean continuity?

"I get 12.5V from R/BL - BR/W , BK/Y-BR/W , Y/W-BR/W" as for the red/blue wire thats only feeding the front panel and front panel indicator lights, i wouldnt be too worried about it, BK/Y-BR/W is correct, as for going the yellow/white wire thats the water temperature probe, without checking my loom im not sure how the resistance of that changes with temperature, but you might be correct that it should give you 12.5V

What exactly burnt out and where?

My thought would be that you have a break in the black wire that connects the CDi, fuel pump, tacho and coil 1+4
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Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Thu May 02, 2019 5:57 pm

New update: i switched the power wires from coil 1 to coil 2. Coil 1(1&4) works, poorly though. I believe it was overpowered. As it gets hot and it has a constant 12.6v(depending on the battery voltage). If I turn the kill switch off the voltage drops to 0.10v. The second coil is at 0.0v
Coil 2&3 has between the red wire and green 0.0v at rest and jumps around 2-3v when cranking.( my multimeter is a cheapy, might not be sensitive enough to capture the short 12v burts)
When testing coil 1&4 between the red wire and black I get 12.6v at rest and when cranking.
When I turn off the kill switch, I repeat the voltage drops to 0.10v(residual?)
Between the BK and BR/W I get 12.6v at Cdi and at the tacho connector. I have continuity on the BK wire everywhere , from the tachometer connector to CDI and the bk coil wire.
I believe the bk wire is shorted somewhere to 12v power, I have power to bk and red wire(at coils) even with CDI disconnected. I found out that if I discconect the right handlebar assembly( start button, kill switch, lights button etc) the voltage between bk and red drops to 0.10v also) Any thoughts?

Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Thu May 02, 2019 6:09 pm

The Short happend at the Back of the loom, Hard to Explain it’s right underneath the seat of you understand what I mean. Like, where the regulator it is. Affected wires the thick white wires(grounds I think, without them no power to the bike) , blue/red, br/w, bk/y . I need to open the loom and check again, there where like 10 wires shorted and melted.
The loom has two copex(hard plastic tubing) protection , the short happend at the last copex protection (the 2nd one as looking from the front of the bike to the back of the bike.) I hope you will understand something from my really bad explanations. Lol

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banner001
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Re: Quick help please, no tacho, lost a cyl or two

Post by banner001 » Thu May 02, 2019 6:22 pm

Ok, if you disconnect the connector block that powers the tacho etc. Can you now fire up the bike?
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Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Thu May 02, 2019 6:24 pm

Already tried that, still starts on 2 cyl only.

Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Thu May 02, 2019 6:44 pm

I forgot to mention the starting relay doesn’t work anymore. I need to short the main two contacts to get it spinning. The relay has stuck closed when the short happend and the bike was cranking continuously even without the key in the ignition. The relay still clicks, between the main two connection I have 12v all the time. I read on the internet that those two contacts should be opened until the relay clicks. That could be my problem? The bike doesn’t crank if I don’t short those two contacts.( the thick ones going to the starter motor). The fuel pump works as well I can hear it prime when I press the started button and the staring really clicks as well though the bike doesn’t crank.

Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Fri May 03, 2019 6:06 am

Please any help or thoughts? Maybe would sound like “first world problems” but I need the bike running as is my main means of transport. I’m thinking of making the big step and get out the full loom and checking it all, but if I can escape that I would be glad.

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Re: Quick help please, no tacho, lost a cyl or two

Post by banner001 » Fri May 03, 2019 8:51 am

Personally i think its new loom time, then start checking all of your peripheral systems...

However, starter motor relay continuity should only be between:
'main terminal that connects to battery' to white wire
bk/y to y/r

You are going to need a new starter relay as yours has an open short...its good only as a paperweight now.

Just refresh me please, so at the moment if you fire the bike up you only have coil 2+3 firing, if you swap over both leads between the two coils do you now only have coil 1+4 firing, or do they all fire, but not well?
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Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Fri May 03, 2019 12:46 pm

Thank you for your patience banner. If I swap the leads between the coils, from coil 2&3 firing it swaps to coil 1&4 firing and the coil 2&3 becomes dead. At the coil terminals the green and red ( coil 2&3) it the rest voltage is 0.00v and when cranking it has like short bursts of power between 2-3v DC.( the coil does fire correctly) At the coil terminals black and red( coil 1&4) I get a constant 12.5v dc, no pulses and the coil does not fire.
The coil 1&4 got hot and I suppose it was affected by that 12.5v dc running continuously as I mesured the coil with the multimeter and now it’s out of spec although it does fire with a weak spark(blue to yellow). If I turn off the kill switch or disconnect the green connector from the right handlebars cluster the voltage from bk and red (coil 1&4 terminals) it does drop to 0.10-0.20v).
I believe one of these things happen: bk shorted to ground, bk shorted to red , or a 12v supply. Most likely to a 12v supply, as o have 12.5v even at the CDI connector without the CDI connected. Instead of a signal I have a 12v supply on the BK wire.

Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Fri May 03, 2019 12:47 pm

I know I need to change the relay as is dead, but first I want to repair the loom and replace the relay and coil 1&4.

Catalin24
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Re: Quick help please, no tacho, lost a cyl or two

Post by Catalin24 » Sat May 04, 2019 10:01 am

How can I test if my CDI unit is bad? Like internal shorts?

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Re: Quick help please, no tacho, lost a cyl or two

Post by banner001 » Sat May 04, 2019 11:04 am

Ok, so it can't be your coil, and if there is no wiring fault, then all that leaves is the CDi...I would replace that, check over all your wiring and then see if it fires up on both coils.
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