disco1001 Posted July 3, 2013 Report Share Posted July 3, 2013 2007 Sherco 250...Running fine for the past 6 mths. Stalled at trial....took 10 mins to get going again...ran for 2 more mins then died as if carb clogged...Would not start again.... On visual inspection weak spark then totally disappeared. no spark......Cleaned all connections / earths...still nothing....No spark. Im going to try a spark tester on the plug....just to confirm loss of current... Is this the best basic method.....sorry dont know how to use a volt meter... Whats the most likely unit failure if spark not there? And how can i eliminate step by step...when replacing parts...which to go for 1st? Any starting points / advice will be much appreciated. Disco Quote Link to comment Share on other sites More sharing options...
jfc Posted July 3, 2013 Report Share Posted July 3, 2013 May be worth disconnecting your kill switch before you get to involved. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted July 3, 2013 Report Share Posted July 3, 2013 Really to make any progress you need to be able to use a multimeter or find someone who can. Just throwing parts at it is a very expensive way to sort the problem. On the stator the ignition system has 2 components, the source coil and the trigger coil. The source coil generates the power and the trigger generates a pulse to tell the CDI the position of the crank - the CDI unit then fires the ignition coil at the right time before TDC. if you can identify the source coil (the large coil with fine windings) it should have a resistance of typically 250 to 350 ohms. The trigger oil is a much smaller "thingy" usually with a metal blade or point near the flywheel. Typically it has a resistance of 1000 to 1200 ohms. I would see if MRS can provide a circuit diagram with wire colours and resistance readings. At Scarborough you are not too far from AG bikes at Reeth who are sherco dealers. Quote Link to comment Share on other sites More sharing options...
disco1001 Posted July 3, 2013 Author Report Share Posted July 3, 2013 Hi JFC......To dissconect kill switch is it just a matter of unpluging at connection in line? or do you need to do something else? Thanks for input so far,,,will eliminate and update... Kill switch & Plug cap & condensor 1st...i think.... Disco Quote Link to comment Share on other sites More sharing options...
b40rt Posted July 3, 2013 Report Share Posted July 3, 2013 Hi JFC......To dissconect kill switch is it just a matter of unpluging at connection in line? or do you need to do something else? Thanks for input so far,,,will eliminate and update... Kill switch & Plug cap & condensor 1st...i think.... Disco Misread sherco for sherpa, ignore my post except change plug and cap, cheap and easy to do, also disconnect kill switch as said. Do one thing at a time so you know what the problem was, hopefully something simple ! Quote Link to comment Share on other sites More sharing options...
disco1001 Posted July 3, 2013 Author Report Share Posted July 3, 2013 thanks again..will do the simple & cheap changes then get it to someone whos handy with bike stators & multimeters if the changes fail.... Quote Link to comment Share on other sites More sharing options...
jfc Posted July 3, 2013 Report Share Posted July 3, 2013 Yep as said above just unplug kill switch if still no spark reconnect and try a new plug. Quote Link to comment Share on other sites More sharing options...
jfc Posted July 3, 2013 Report Share Posted July 3, 2013 Sorry make sure the metallic part of plug is touching the cylinder head or some other metallic part of the bike when testing for a spark. Sorry if that is patronising but some times it is easy to assume someone knows and if they don't we could run round in circles for ever. Quote Link to comment Share on other sites More sharing options...
zippy Posted July 3, 2013 Report Share Posted July 3, 2013 hold the plug in your bare hand and have a really good buddy kick the bike over very quickly. you will know real fast if you have juice at the plug, Quote Link to comment Share on other sites More sharing options...
copemech Posted July 4, 2013 Report Share Posted July 4, 2013 (edited) Really to make any progress you need to be able to use a multimeter or find someone who can. Just throwing parts at it is a very expensive way to sort the problem. On the stator the ignition system has 2 components, the source coil and the trigger coil. The source coil generates the power and the trigger generates a pulse to tell the CDI the position of the crank - the CDI unit then fires the ignition coil at the right time before TDC. if you can identify the source coil (the large coil with fine windings) it should have a resistance of typically 250 to 350 ohms. The trigger oil is a much smaller "thingy" usually with a metal blade or point near the flywheel. Typically it has a resistance of 1000 to 1200 ohms. I would see if MRS can provide a circuit diagram with wire colours and resistance readings. At Scarborough you are not too far from AG bikes at Reeth who are sherco dealers. I know you are trying to help here, but this would be a Leonelli digital hall effect system. My motto on these is simply "Resistance is Futile"! (with minor exception of fully open or shorted failure mode of the sensors) Add to that, seems he is ill equipped to run what ohm meter checks are available. Thus, back to basics, install new sparkie, Chech earthing on CDI unit and disconnect kill wire. Etc. Over and above that, take to dealer or contact Splatshop for parts to swap out, but if one is technically challenged, swapping a stator in not as easy as it sounds. Look what happened to Zippy! Edited July 4, 2013 by copemech 1 Quote Link to comment Share on other sites More sharing options...
zippy Posted July 4, 2013 Report Share Posted July 4, 2013 Don't know what you talking about Cope? I feel fine :hyper: :hyper: :hyper: Quote Link to comment Share on other sites More sharing options...
disco1001 Posted July 4, 2013 Author Report Share Posted July 4, 2013 (edited) Update: Took the plug cap off the ht lead, removed plug from barrel and cranked by hand..held lead in hand..SPARK...is back????? if this was the stator...would this happen...anyway reconnected all and tried to kick of.....nothing...again... The ht lead when plug and cap is in position is so short with a shcoking right angle....also outer sleave lining split.....is this ok..normal for this Sherco...my sons beta & GG are much longer with no right angle bends... Wondering if im losing spark because the seriously short lead and tight bend.....maybe arhcing across somewhere? Going to fit new plug cap tomorrow to see if it does the same....if it does maybe its time for an new CD? or will the HT length be the same? thats my worry? All suggestions / experiences appreciated... Edited July 4, 2013 by disco1001 Quote Link to comment Share on other sites More sharing options...
jfc Posted July 4, 2013 Report Share Posted July 4, 2013 Have you tried a new plug? Plugs can breakdown under compression! Quote Link to comment Share on other sites More sharing options...
disco1001 Posted July 4, 2013 Author Report Share Posted July 4, 2013 yes been switching between 2 Quote Link to comment Share on other sites More sharing options...
dadof2 Posted July 4, 2013 Report Share Posted July 4, 2013 Zippy #9 - don't do this - it can wreck your CDI, I will post why when I have more time. Disco - I guess you will try a new plug cap - they usually contain a resistor that can fail. Quote Link to comment Share on other sites More sharing options...
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