bodgit0_0 Posted January 31, 2009 Report Share Posted January 31, 2009 Went to start my 1995 250 beta techno this morning, it gave a slight chuff and now wont run. There is power going to the electric fan but no spark. All connections appear good. Can anyone adize on what checks I can carry out to confirm if the coil is good. There is a couple of black boxes under the tank area which I would like to check over as well. Cheers for any advice Quote Link to comment Share on other sites More sharing options...
jimw Posted January 31, 2009 Report Share Posted January 31, 2009 Check whether you have power to the low tension side of the coil - if so check the low tension circuit is intact by using meter or bulb and battery. Let me know the results Regards Jim Quote Link to comment Share on other sites More sharing options...
bodgit0_0 Posted January 31, 2009 Author Report Share Posted January 31, 2009 where do \i check for the power. There are cables coming up fron the fly wheel, one goes to a black square item with a wholein the centre. this then feeds the fan which runs perminatly. the rest of the cables go to the coil and a box with 3 connections on it. pressume if i kick it over i should find power or should i put a slow drill on the fly wheel??? cheers lee Quote Link to comment Share on other sites More sharing options...
dan williams Posted January 31, 2009 Report Share Posted January 31, 2009 Check the basics first like stuck kill switch, shorts in the wiring (rubs to frame), poor contact for grounds, whisker of carbon on the plug tip. Quote Link to comment Share on other sites More sharing options...
bodgit0_0 Posted January 31, 2009 Author Report Share Posted January 31, 2009 Here goes.... Have checked for power (wobbly volts) at the coil on the following cables Red=None found Green=24 ish on the multi meter. White=None found These are the cables that come direct from the fly wheel. In addition to the above there is a brown cable that goes to what I would pressume to be rectifier then out to the ???condenser??? which powers the fan. Whats next for me to check?????? Did notice the coil is a ducatti type?? with the 3 cables going in and the stop cable coming out(have diosconnected this out cable to be sure its not the cause) Have removed the spark plug and popped a screwdriver in to see if a spark is present, but no??? Cheers Lee Quote Link to comment Share on other sites More sharing options...
yamahaty250xox Posted January 31, 2009 Report Share Posted January 31, 2009 sounds like a sheared woodruff key to me. My dads sparked up one day and died instantly. turned out to be the woodruff key. hope this helps max Quote Link to comment Share on other sites More sharing options...
stork955 Posted January 31, 2009 Report Share Posted January 31, 2009 No spark is probably a failed Stator. Search around previous threads, there are many on this topic. You are on the right track with your testing, the CDI is very rarely at fault, the coil is slightly less likely to be a problem. Cheers, Stork Quote Link to comment Share on other sites More sharing options...
pete_scorpa3 Posted January 31, 2009 Report Share Posted January 31, 2009 Sadly it does sound like the stator. You can get them rewound fairly cheaply if that is the case. Quote Link to comment Share on other sites More sharing options...
bodgit0_0 Posted January 31, 2009 Author Report Share Posted January 31, 2009 The woodruff key is good hence the fan power supplied. and i can see the flywheel turning. Where does the power for the fan come from if the stator is at fault for the spark????? Can anyone recommend any other tests for the stator, and where could I get it rewound. Cheers Quote Link to comment Share on other sites More sharing options...
nzralphy Posted January 31, 2009 Report Share Posted January 31, 2009 One chuff and it stops.... I'd say the Woodruff key is sheared. The flywheel will look fine and appear tight, while the electrics to the fan will also appear fine. To check this you must remove the flywheel. Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 1, 2009 Report Share Posted February 1, 2009 The best method is still a timing light. Quote Link to comment Share on other sites More sharing options...
desertrat28 Posted February 1, 2009 Report Share Posted February 1, 2009 (edited) One chuff and it stops.... I'd say the Woodruff key is sheared. The flywheel will look fine and appear tight, while the electrics to the fan will also appear fine. To check this you must remove the flywheel. Ditto that and the timing light. Mine did the same thing and it was a sheared Woodruff key. Edited February 1, 2009 by desertrat28 Quote Link to comment Share on other sites More sharing options...
stork955 Posted February 1, 2009 Report Share Posted February 1, 2009 Gday all, If the woodruff key has sheared it will still have spark! (Just at the wrong moment...)So this is not the problem here as Lee has said it has no spark... We need some good wiring diagrams for Beta's so I can post diagnosis procedures for the ignition systems on them. Anyone? I dont even have a good one for my 99 Techno... Lee, your stator will likely have 3 main parts - a Source coil to power the ignition, a lighting coil to power the lights and the trigger to tell the CDI when to spark. If you can work out which is which you should see around 50 to 70 volts AC from the source coil when kicking (take the plug out to make it easier), about 30 volts AC from the lighting coil and about 1 volt AC from the trigger. generalyy any coil will fail to open circuit so you do a simple resistance test on each to ground and there should be a minimum of an ohm or two on any coil. Zero resistance is not good. Individually the source coil will probably be around 300 ohms, the trigger around 150 ohms and the lighting coil ??? - not much, maybe under 100. That wont affect ignition anyway. Also - the flywheel must have strong magnetism - it is not unknown for flywheels to lose their "grunt" and lower coil outputs, but usually on very old bikes. The ignition coil is pretty easy, test the primary side with an Ohm meter - you should see about 2 ohms to ground and roughly 20 000 - 30 000 across the secondary (spark plug) side. Significantly more or less means the coil is no good. Check the plug cap too - these are known to fail - you may notice a high reading on the secondary side, remove the plug cap and then it looks OK will tell you that this is at fault. Some plug caps are deigned to have some resistance, typically 5k ohms, if this is the case allow for it and replace it with the same type! (using non-resistor caps on systems designed for them can make the CDI fail... you have been warned!) HTH, Cheers, Stork. Quote Link to comment Share on other sites More sharing options...
bodgit0_0 Posted February 4, 2009 Author Report Share Posted February 4, 2009 A quick update on what I have found. The w-key is sound. The flywheel was a challenge to remove but came off with a good plastic hammer as to not upset the magnets. The Trigger resistance is spot on, so is the light/fan system. The problem turns out to be a low resistance from the coil power system, it should be 450 but came thru at 250 ish..... Hoping to have it back on Friday to refit and test ride. Cheers for everybodys input, I definatley need to find some better diagrams and info about the electrickery. Lee Quote Link to comment Share on other sites More sharing options...
stork955 Posted February 5, 2009 Report Share Posted February 5, 2009 That will do it. A low resistance indicates some shorted coils which will reduce the coils' output. Good work finding it. I should point out that a flywheel puller is a good tool to have, hammering the flywheel off is fraught with danger - both to the flywheel itself and the main bearings and crankshaft. Available cheaply from any bike shop. Cheers, Stork Quote Link to comment Share on other sites More sharing options...
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