Coil Issue

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Edd
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Coil Issue

#1 Post by Edd » Tue Apr 02, 2013 8:27 am

Hi Guys;

Some assisstance will be greatly appreciated. I had a faulty top coil tested out of specification. However when I start the bike the no 4 cylinder was firing intermitantly and no 1 cylinder was firing correctly that lead me to testing the coil. Played around with leads and when I changed the orange and black wire around on the coil the problem transfered to no 1 cylinder. Is my problem not cdi and that damages the coils?

Edd

Edd
Posts: 79
Joined: Fri Jun 11, 2010 9:44 pm

Re: Coil Issue

#2 Post by Edd » Fri Apr 05, 2013 8:43 am

Hi Gents;

Been doing some reading on misfires and coil problems. I have read that the orange wire is the positive and the black wire the negative on the coil. If this is the case then why do I transfer the problem from one cylinder to another if I turn the wires around :smt017 . On my tzr 250 3ma I can connect the wires any way around no effect. I was under the impression the wires send the signal to the coil left and right not negative positive.

I replaced the old coil with a new one did the bottom one a few months back. Both top cylinder were now firing and running well on idle. No 3 started miss firing on idle changed the plug looks like i solved the problem 3rd plug I had to change in 200km. I do however now have a misfire from 4000 rpm to 8000 rpm :smt014 .
Can this be a earth problem.

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Andrew
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Re: Coil Issue

#3 Post by Andrew » Fri Apr 05, 2013 11:45 am

:smt017
HT Lead :idea: That's where I'd start.
Get the bike running at night in the garage, switch off all the lights (it's got to be VERY dark), and check to see if you can see any arcing when you rev the bike from 4K - 8K.
Is the rev counter playing up and bouncing around when you hear the misfire when revving it???
Andy (UK)
RZV500R
FRC
Faster Faster !!!

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Andrew
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Re: Coil Issue

#4 Post by Andrew » Fri Apr 05, 2013 11:46 am

Forgot to add... you'll have to lift the tank when doing these checks. You're looking for an arc between the leads and ground.
Andy (UK)
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2smoke
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Re: Coil Issue

#5 Post by 2smoke » Fri Apr 05, 2013 8:53 pm

Changing the orange and black wires should not make a difference. Any chance it was a coincidence?
Are you sure this is a plug misfire and not a carb problem(flooding,studder, etc.)
I would start with the basics. Check compression and case seals. Then completely rebuild the carbs.
You should not be changing plugs at all. They dont foul plugs when running right.
Colin

Edd
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Re: Coil Issue

#6 Post by Edd » Sun Apr 07, 2013 1:44 am

Hi Guys;

Just typed a full book report and lost the lot :smt013 .

Just history on the bike and electrical problems. Complete engine re build every gasket and every single seal a year back. Also did the carbs that time complete rebuild I have set floats then and bike was running well. Struggled a bit to get the setup right with jim lomas pipes :smt001 .

Changed bottom coil 6 months back no3 was not firing, changed top coil two weeks back no4 was not firing. Every time on cold start up it will function and as soon as heat gets into the pipes no spark. In both cases plugs were changed.
On the last coil change I had a misfire and bike back fires on no3 again changed the plug and it was better. But bike was now misfiring from 4000 to 8000 and low on power. Rev counter is stable under acceleration. I will do the dark room test this week and also test the stator to see if signal to cdi is correct.
I am also leaning towards cdi damaged or maybe the timing is out.

Edd

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Rick Lance
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Re: Coil Issue

#7 Post by Rick Lance » Sun Apr 07, 2013 8:46 am

Did you paint the motor and frame? Have you disturbed your ground by doing so? A bad ground will allow the ignition to fire properly until resistance builds up and then you will lose one cylinder at a time until the bike quits. Might I suggest that you run dedicated ground wires from each coil and the motor to the chassis?

Edd
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Re: Coil Issue

#8 Post by Edd » Sun Apr 07, 2013 2:26 pm

Hi.

No havent painted the motor and frame still on to do list. Where does the wiring harness earth on the chasis as I know mine is not correct bike has caught fire before as some of the lpugs have slight fire danage. My earth is under the tank connected to one of the bolts that bolts the heat deflection plate down.

Edd

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Re: Coil Issue

#9 Post by Edd » Mon Apr 08, 2013 11:36 am

Hi Guys;

Did a search last night for spark jumping, nothing only the washers on the plugs were glowing blueish light and very feint but all four are doing this.

Edd

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Andrew
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Re: Coil Issue

#10 Post by Andrew » Tue Apr 09, 2013 9:58 am

Edd wrote:Hi Guys;

Did a search last night for spark jumping, nothing only the washers on the plugs were glowing blueish light and very feint but all four are doing this.

Edd
Edd
When I found my spark jumping from one of the top HT lead to the chassis, I had the rev counter going mad jumping all over the place at the same time.
Electronic rev counter interference from voltage on the ground circuit.

Still, double check all your earth connections.
Andy (UK)
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Faster Faster !!!

Edd
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Re: Coil Issue

#11 Post by Edd » Tue Apr 09, 2013 2:47 pm

Hi Andrew,

My rev counter is good same as always. Can this be a timing issue though?

Edd

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