seldredge Posted October 12, 2015 Report Share Posted October 12, 2015 Bikes runs well for 15 or 20 minutes and then the motor dies. No spark. After it cools I can start it again and ride it for 15 minutes or so, and then the motor dies again. Dealer had the bike and couldn't diagnose or fix. Any ideas? I thought perhaps it was related to the cooling system since the engine dies about the time the fan would come on, but I'm not sure how to check that. Quote Link to comment Share on other sites More sharing options...
seldredge Posted October 12, 2015 Author Report Share Posted October 12, 2015 (edited) The probabilty is that one of the coils by the flywheel is failing when it gets hot. Check the ohms according to this diagram. http://www.trialspartsusa.com/diagrams/KokusanDigital2005Pro.jpg Check first when it is cold and then when it is hot and the spark quits. The ohms reading will change a little from hot to cold but there will be a big difference in the reading of the bad coil. Thank you. I'll check this, or find someone who can. But my bike has a Ducati system, not Kokusan. Edited October 12, 2015 by seldredge Quote Link to comment Share on other sites More sharing options...
seldredge Posted October 12, 2015 Author Report Share Posted October 12, 2015 I READ SOMEWHERE OF A SIMILAR PROBLEM, AND THAT TURNED OUT TO BE THE PICK-UP MODULE FAILING...... I found that thread some time ago and bought the part listed. I think it was about $70 by the time I got it (UK to US). I couldn't try it. Description said it was go Gas Gas, but it couldn't be mounted in my bike. It's bigger than the space available, even after drilling and grinding. Quote Link to comment Share on other sites More sharing options...
sectionone Posted October 13, 2015 Report Share Posted October 13, 2015 Did you buy this part? http://www.electrexworld.co.uk/acatalog/P7.html It has the same 30mm bolt spacing but is 228 ohms instead of the 250 ohms of the original GG part. I'm having the same problem with the same bike except it won't always get spark again after it cools down. Sometimes it does, sometimes not and sometimes spark returns after fiddling with wires then it will run for about 20 minutes until it dies and no spark again. Sometimes it will run shorter, anywhere from 3 to10 minutes, but usually about 15 minutes average. This last time, I rode 20 minutes, bike died with no spark, I let bike sit for 5 hours, still no spark, then I unbolted pickup coil, then bolted back on and spark returned. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted October 13, 2015 Report Share Posted October 13, 2015 (edited) Do not fiddle with the wires between stops / starts - that could confuse the issue. The most likely fault is in a fine wire component such as the HT coil, Ignition source coil or timing trigger coil. On 2007 GGs the source and trigger coils are the most suspect. As the engine and electrics warm up a poor connection becomes poorer due to the thermal expansion and movement of the components. These components will still have faults when cold but the electrical variations caused by the faults will be so small they will need an oscilloscope to see them. You could try a road motorcycle engineer who has this sort of equipment / knowledge If the spark is good / normal when the bike is cold the likely fault is the trigger coil If the spark is poor or weak when cold the source coil is the most likely followed by the HT coil. A constant period before being able to restart of 15 to 20 minutes is fairly typical of HT coil failure Edited October 13, 2015 by dadof2 Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted October 13, 2015 Report Share Posted October 13, 2015 (edited) I would start at that last part. Common problem also with normal road bikes. Difficult to find because of the time period. Easy to swap so I would try that first. Also you should be able to measure a difference in ohn hot and cold with engine off. Edited October 13, 2015 by crazybond700 Quote Link to comment Share on other sites More sharing options...
sectionone Posted October 15, 2015 Report Share Posted October 15, 2015 After fiddling with the wires more I was able to ride for an hour without any issues. First I replaced the two wires going to the trigger coil. Then I noticed the two wires coming from the stator were not where they should be. Behind the trigger coil is a thin shaped metal piece with a channel that keeps the two wires away from the flywheel. The wires were not in the channel so I put them back in. I'm not sure which procedure did the trick but I had a full hour of riding without losing spark and will see if this continues. Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted October 15, 2015 Report Share Posted October 15, 2015 Bikes runs well for 15 or 20 minutes and then the motor dies. No spark. After it cools I can start it again and ride it for 15 minutes or so, and then the motor dies again. Dealer had the bike and couldn't diagnose or fix. Any ideas? I thought perhaps it was related to the cooling system since the engine dies about the time the fan would come on, but I'm not sure how to check that. where are you? Quote Link to comment Share on other sites More sharing options...
baldilocks Posted October 15, 2015 Report Share Posted October 15, 2015 I had my bike apart for a few weeks tidying it up to sell it a couple of years ago. New owner rang and said it keeps cutting out and the fan doesn't work? I had connected the temperature sensor to the kill switch circuit in error so when the bike got warm enough for the fan to start it killed the engine. Have you done the same ? Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted October 15, 2015 Report Share Posted October 15, 2015 I had my bike apart for a few weeks tidying it up to sell it a couple of years ago. New owner rang and said it keeps cutting out and the fan doesn't work? I had connected the temperature sensor to the kill switch circuit in error so when the bike got warm enough for the fan to start it killed the engine. Have you done the same ? Hahaha, im sorry but I like that! Good tip to look at! Quote Link to comment Share on other sites More sharing options...
baldilocks Posted October 15, 2015 Report Share Posted October 15, 2015 (edited) I couldn't believe id done it but it was a cheap fix Edited October 15, 2015 by baldilocks Quote Link to comment Share on other sites More sharing options...
sectionone Posted October 19, 2015 Report Share Posted October 19, 2015 I rode a full day without losing spark. The last two steps solved it, either replacing the wires to the trigger coil or routing the two wires from the stator back into its channel. The other things I did before didn't solve it: replacing spark plug wire and connection junction plug to coil. Quote Link to comment Share on other sites More sharing options...
seldredge Posted October 19, 2015 Author Report Share Posted October 19, 2015 where are you? I'm in California, south of San Francisco. Would have answered sooner but I'm not getting notifications from the thread. Not sure why. Quote Link to comment Share on other sites More sharing options...
seldredge Posted October 19, 2015 Author Report Share Posted October 19, 2015 I had my bike apart for a few weeks tidying it up to sell it a couple of years ago. New owner rang and said it keeps cutting out and the fan doesn't work? I had connected the temperature sensor to the kill switch circuit in error so when the bike got warm enough for the fan to start it killed the engine. Have you done the same ? I'll check. That sure fits the symptoms. Was going to test today to see if the fan comes on before the engine stops because I wondered if there was a connection. Quote Link to comment Share on other sites More sharing options...
seldredge Posted October 19, 2015 Author Report Share Posted October 19, 2015 Did you buy this part? http://www.electrexworld.co.uk/acatalog/P7.html It has the same 30mm bolt spacing but is 228 ohms instead of the 250 ohms of the original GG part. I'm having the same problem with the same bike except it won't always get spark again after it cools down. Sometimes it does, sometimes not and sometimes spark returns after fiddling with wires then it will run for about 20 minutes until it dies and no spark again. Sometimes it will run shorter, anywhere from 3 to10 minutes, but usually about 15 minutes average. This last time, I rode 20 minutes, bike died with no spark, I let bike sit for 5 hours, still no spark, then I unbolted pickup coil, then bolted back on and spark returned. No, I got this one: http://www.electrexworld.co.uk/acatalog/P1.html Although where I ordered from--I don't remember it saying Kokusan or providing spacing info, or I wouldn't havea bought it. Just said Gas Gas Quote Link to comment Share on other sites More sharing options...
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