hey guys,

just looking to bounce this off someone, its been covered 100s of times over but that just means 100s of people should have plenty of experience with it

im not all that experienced in the theory behind electrics, i'll say that right now but i have worked on them several times so I'm not completely useless.

first things first i have shortened most of my wiring loom to hide it inside the frame (soldered/heatshrunk), I've run the bike for 2-3 weeks with the modified wiring loom with no hassle. (alarm bells ring right) although its likely the culprit lays in that fact I have checked for relevant continuity and for extra resistance where it shouldn't be and everything checks.

for anyone interested theres a link to my build thread in the comments section in my profile.

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initial symptoms were that i was riding along and much like when a MAF sensor (or equivalent) goes in a car, it begins to 'kangaroo' for lack of better term (like it goes from no power to normal power to no power) and then it cut out like it had run out of fuel or weak spark. tried to restart it and the starter would spin but the bike wouldn't fire.

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so,

no blown fuses.

there is fuel in the carbs bowls.

the starter spins, which importantly rules out any of the kill switches (the usual suspects)

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no spark from either coil, i did a primary resistance check on the coils for arguments sake even though its incredibly unlikely that both coils and 4 ht leads would fail at the same time.

left coil (2-3) has continuity through its positive feed to the cdi box and the fuel cut relay. it's negative feed has continuity through the 2nd coils negative feed, the engine stop switch and fuel cut relay like it should.

right coil (1-4) the positive feed has continuity to the cdi box and the negative replicates that of the left coil as they are linked in together.

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two things I'm thinking right now is that,

i potentially have a faulty fuel cut relay as its part of the circuit to the coils. I'm not sure if the starter would work if thats true as its tied into the engine stop switch. easy test would be to pull it off and see if the starter spins.

or... my second line of thought. i tested the ignition pulse pickup as far down the line from the cdi box to its connector and found it to be 440 - 450ohm, 10-20ohm less than the normal minimum operating range of 460 - 580. now thats not a huge amount but I'm aware that electrics can be very sensitive to this kind of thing. my understanding is that less resistance = more current = more heat = less life expectancy. of course this travels to the cdi box, so it may be fried. perhaps I'm pulling at straws here. i can't remember if i did but removing a section of this cable may have interfered with the required resistance.

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any inputs would be appreciated here, perhaps I'm overlooking something.

thanks to anyone who responds =]

 

Do you have power at the coils?

 

hey 74demon, cheers for the response. i can say that i am getting battery power at the coils. i think I've found the problem as well, looks like the ignition pulse generator.


here's my troubleshooting notes.



Left coil. Ht leads off plugs. 3.1 ohm // ht leads attatched 3.0 to 3.1

right coil replicates above.

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whilst connected, left and right coil positive feeds get battery voltage when ignition is off or on. To ground ^

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left coil attatched to posi feed gets 9v to ground

right coil posi gets variable readings 9 through to 13 to ground

not a concern if it reads differently ^^ so long as both are higher than standard value.

should read 100v minimum

directs to 16-3 in the manual. Indicates faulty icm.

don't think thats the heart of the problem though, doesn't seem like the power was getting as far as that.

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removed fuel cut relay to see if the starter would spin without. still spins. Crossed the wires to make sure it was connecting, made no difference to coils.

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left coil posi feed to icm = 0.4 to 0.5ohm on the 200 scale.

Right coil replicates

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right coil neg feed to icm 3.2ohm
left coil replicates

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left coil neg feed 0.5 ohms to both engine cut off killswitch on the bars and to the fuel cut relay

right coil replicates the same results^^

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at icm peak voltage on 16p connecter with starter cranking is 0.2 /

should be 0.7v minimum

icm voltage at 2p connector replicates 0.2 .

still out of spec so this indicates that from the icm to the 2p connector is fine.

it is possible that its just the wire from the pulse generator to the connector is damaged. but i am going to investigate that later on.

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battery is currently charging to see if it changes the results but i don't think it will. so it looks like the pulse generator is at fault. it is still possible that it has fried the icm on its way out.

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i know i jump about calling it a cdi / icm / ecu / spark box and god knows what else but if anyones trouble shooting themselves these are pretty much the same thing lolz

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any comments are still appreciated.
thanks =]

 

going to post this in a new thread as well and with some luck someone will be able to say.

just replaced the pulse generator with one from an f2, exact same item that was already in there. the orangey tan coloured one rather than the red one thats meant to be in the f3.

and it's still giving me a reading of 0.2v rather than the 0.7 it needs. it also gives 440-450 ohms resistance when the minimum is 460, i am going to double check with another multimeter just to be safe here.

so here we go, i need a favour from someone with a working ignition circuit. i need to know what resistance you have between the positive feed at the coil to the 16 point connector at the icm? the 0.4-0.5 I'm getting seems abnormal to me but there is no mention of this in either the f2 or f3 manual. also to see if you still get the same resistance between the negative side and the fuel cut relay or cut off switch on the bars.

my reason for asking is that i still suspect that the icm unit may have failed and if it has there has to be a reason as to why, resistance causes heat and heat causes failure. this is the only area I'm having a problem with.

you would be doing me a huge favour!