Intermittent Spark
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ogman
- Settled in member
- Posts: 7
- Joined: Tue Oct 12, 2010 12:05 pm
Intermittent Spark
Hi all, I am still struggling getting my gk76 to go. sometimes when I press the starter I get a spark at the plugs and other times not. When I have a plug out of the bike and earthed down, I notice that I have to press the starter repeatedly to get a spark going. Then it either stays sparking or just dies after a couple of seconds.
Does any one have any thoughts please.
Ta..... Ian
Does any one have any thoughts please.
Ta..... Ian
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Andy
- Settled in member
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- Joined: Fri Mar 20, 2009 6:55 pm
- Bike owned: R1x2 98/2k/Gp125/73a/76a/76a
- Location: Lincolshire
Re: Intermittent Spark
Hey,
Check all connections and make sure they are clean/good etc,if it persists and the plugs are proven beg/borrow another set of coils of another bike(one will do) and try that,i`m running R1 coils on mine at the moment and there fine....
Had some really weird results with dodgy coil`s in the past, i keep a proven coil on the shelf now and it`s one of the first thing`s i test apart from the obvious. Hope that help`s mate....
Andy
Check all connections and make sure they are clean/good etc,if it persists and the plugs are proven beg/borrow another set of coils of another bike(one will do) and try that,i`m running R1 coils on mine at the moment and there fine....
Had some really weird results with dodgy coil`s in the past, i keep a proven coil on the shelf now and it`s one of the first thing`s i test apart from the obvious. Hope that help`s mate....
Andy
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Andy
- Settled in member
- Posts: 163
- Joined: Fri Mar 20, 2009 6:55 pm
- Bike owned: R1x2 98/2k/Gp125/73a/76a/76a
- Location: Lincolshire
Re: Intermittent Spark
I`ve also had a similar problem with a corroded kill swith on one of 73`s which gave similar symptom`s,just a thought.....
Andy
Andy
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ogman
- Settled in member
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- Joined: Tue Oct 12, 2010 12:05 pm
Re: Intermittent Spark
OK, thank you for giving your time to respond. I will try and scrounge some coils to try.
hanks.... Ian
hanks.... Ian
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Variablevalves suck
- Site Supporter
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- Bike owned: GSXR Carb o'ring kits supplied
- Location: Stoke-on-trent
Re: Intermittent Spark
Is the bad spark on all plugs? as if you only check plug 1 or 4 they fire from the same coil so its worth trying 2 and 3 also as its unlikley both coils will go at once.
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dobbslc
- NWAA Supporter
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- Joined: Fri May 02, 2008 8:06 pm
- Bike owned: 3TJRRSP TRX850 XV750 cafe
- Location: Hertfordshire
Re: Intermittent Spark
I've got the same problem on mine, intermittent spark then no spark then a spark 5 seconds after I've stopped cranking???
I was poking around behind the clocks & right under the inside of the headstock to check the connections & then disconnected one coil and tried it and got a good spark!
I reconnected the other coil and got 4 good sparks, Not sure what I disturbed but will go through all the wiring again. The coil live feeds seem to go up to the clocks somwhere.
I did find a diode by the left rear seat sub frame that is somthing to do with the stand & neutral switch cut outs that was corroded so cleaned this, it's about 15mm x 10mm in size with 3 pins and very tight to the sub frame. Make sure it goes back in the right way or you will have made another problem for yourself!
I will keep a record of what I've done and post it here if I find the real fault as there seems to be loads of ignition faults on these bikes causing people trouble. I hope the CDI is ok
I was poking around behind the clocks & right under the inside of the headstock to check the connections & then disconnected one coil and tried it and got a good spark!
I reconnected the other coil and got 4 good sparks, Not sure what I disturbed but will go through all the wiring again. The coil live feeds seem to go up to the clocks somwhere.
I did find a diode by the left rear seat sub frame that is somthing to do with the stand & neutral switch cut outs that was corroded so cleaned this, it's about 15mm x 10mm in size with 3 pins and very tight to the sub frame. Make sure it goes back in the right way or you will have made another problem for yourself!
I will keep a record of what I've done and post it here if I find the real fault as there seems to be loads of ignition faults on these bikes causing people trouble. I hope the CDI is ok
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ogman
- Settled in member
- Posts: 7
- Joined: Tue Oct 12, 2010 12:05 pm
Re: Intermittent Spark
That sounds like exactly the same as my problems.
I will check out that connector block and keep my fingers crossed.
Ta very much.
I will check out that connector block and keep my fingers crossed.
Ta very much.
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dobbslc
- NWAA Supporter
- Posts: 693
- Joined: Fri May 02, 2008 8:06 pm
- Bike owned: 3TJRRSP TRX850 XV750 cafe
- Location: Hertfordshire
Re: Intermittent Spark
OK went back to it and cleaned everything I could find only to find I've got no spark again 
I'm going to use an oscilloscope to try and find where the signal is getting lost as I'm not sure if the cdi is getting sent a signal or weather it's not sending a pulse to the coils.
Do these bikes have a clutch switch? as there is a mount for one but I can't find any wiring.
edit:
OK I went over the connections again and now seem to have a good spark, The scope showed that the ecu is getting a signal and it's sending a signal to the coils.
we gave the wiring a good pull about while on the scope with no missing pulses so I hope that part is fixed now
Rebuilt the carbs with some new O rings then put it all back together, filled with oil and water and got it started
OH F**k
It ran ok but smoked like a "son bitch".
Looks like the head gasket has gone with oil pissing out the front of the barrels & some mayo in the oil when drained out.
I took it apart and it looks quite clean inside so I will just replace the gaskets & valve oil seals & possibly skim the head with maybe a clean up of the ports etc while I'm in there.
Project "reject" TBC
I'm going to use an oscilloscope to try and find where the signal is getting lost as I'm not sure if the cdi is getting sent a signal or weather it's not sending a pulse to the coils.
Do these bikes have a clutch switch? as there is a mount for one but I can't find any wiring.
edit:
OK I went over the connections again and now seem to have a good spark, The scope showed that the ecu is getting a signal and it's sending a signal to the coils.
we gave the wiring a good pull about while on the scope with no missing pulses so I hope that part is fixed now
Rebuilt the carbs with some new O rings then put it all back together, filled with oil and water and got it started
OH F**k
It ran ok but smoked like a "son bitch".
Looks like the head gasket has gone with oil pissing out the front of the barrels & some mayo in the oil when drained out.
I took it apart and it looks quite clean inside so I will just replace the gaskets & valve oil seals & possibly skim the head with maybe a clean up of the ports etc while I'm in there.
Project "reject" TBC