garrym Posted March 16, 2014 Report Share Posted March 16, 2014 We've had an electrical issue on my lad's GG TXT 70 Rookie, 2003. There was no spark, so first things first, checked the plug, it was fine, so digging a bit deeper, all the earth connectors are ok, the HT lead is fine, as far as we can tell. My dad checked these with a multi meter, I know nothing about electrics but the meter beeped so he was happy with it. Next, we checked the resistance on the wires coming up from behind the flywheel to the little control unit, and we didn't get a reading on the meter when I kicked the engine over. Does this sound like the stator? The wires disappear behind the back of the flywheel so we can't check the connection at that end. Is it possible/advisable to get the flywheel off to look. And is the stator something that we can replace ourselves? Any wisdom gratefully received. Quote Link to comment Share on other sites More sharing options...
jonboy883 Posted March 16, 2014 Report Share Posted March 16, 2014 The fly wheel needs to come off and you'd be surprised at the amount of times a rubbed wire can stop play. Stators are best left to people that know, lots of firms are out there, I've used West Country Windings before, but they may be others on this site who can say whether there are issues with these Stators. Take the fly wheel off and have a good visual check..... Good luck... Quote Link to comment Share on other sites More sharing options...
clay Posted March 16, 2014 Report Share Posted March 16, 2014 As above, West Country windings 5 star service. Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted March 16, 2014 Report Share Posted March 16, 2014 Did you check to see if the kill switch had shorted to ground or was stuck in the "kill" position? That will make for no spark. It is possible to get the flywheel off but you need a special puller. Almost impossible to remove without this special puller. There are no points on the electronic ignition so the small "beep" meter may not be adequate to check for pulse. Electronic ignitions generally use a hall effect sensor to trigger the spark. They are usually mounted on the stator. Stators are essentially a wire wound around a metal core. The windings rarely fail. When they do they usually look cooked. Stators are easy to replace once you get the flywheel off. If you take the flywheel off be careful to not lose the little thumbnail shaped "woodruff key." That is needed to get the flywheel properly timed to the crankshaft. As Jonboy said above, it could be a wire that has worn through its insulation and grounding (earthing) the wire or wearing through the wire. This can be seen with close inspection after removing the flywheel. Hall effect sensors do fail but give no visual cue. They are comparatively cheap compared with having the stator rewound or replaced. Many times people replace the whole stator ($150 - $200 ) when just the sensor ($5 - $15) has failed because of not knowing how to properly test each part. The challenge is getting a part number of the sensor and finding a source. Then it would need to be soldered into place. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted March 16, 2014 Report Share Posted March 16, 2014 If your lad knows what he is doing with a multimeter have a look at http://www.trialspartsusa.com/diagrams/DucROOKIE.jpg and see what readings you get. Beep continuity checks are not that useful Static resistance checks are a little better but Proper diagnosis requires the engine to be spun(use power drill) and measurements taken with an oscilloscope. Quote Link to comment Share on other sites More sharing options...
garrym Posted March 16, 2014 Author Report Share Posted March 16, 2014 Thanks to all for those nuggets! I guess the next step is to remove the flywheel. There's a nut in the centre that seems to be impossible to remove, it just turns the wheel when in gear and the brakes aren't strong enough to hold it still to loosen it, Will penetrating oil help? Looks like I may have to shell out for one of my local bike shops to have a look, either that or put the kid up for adoption! Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted March 17, 2014 Report Share Posted March 17, 2014 To get that nut off you either need to hold the flywheel from turning with a tool or you need to use an air gun (I think called a wind gun in UK). Even after getting the nut off, you will need a puller to get the flywheel off. Not a regular gear puller, but one made to screw into the flywheel center. It might be advisable to take the bike to a shop. Quote Link to comment Share on other sites More sharing options...
garrym Posted March 17, 2014 Author Report Share Posted March 17, 2014 I agree, Thats_A_five, I need three pairs of hands for a job like that and I can see the first aid kit coming out if I try! Time to admit defeat I think. BTW, I disconnected the kill switch in the forlorn hope that it was the culprit. Many thanks to all for your advice. Quote Link to comment Share on other sites More sharing options...
tltel Posted March 17, 2014 Report Share Posted March 17, 2014 (edited) Hi, when you say checked plug and it was fine, is that just a visual check or did you try it in something else,? a plug that looks new can still fail. Try it with a new or different plug. As suggested, disconnect kill switch wires and try for spark, if still no spark, re-connect it. Check HT lead and cap are tight. Then on to flywheel. You really wont get that off without a puller, they cost around £20. assuming the flywheel is the same design as the bigger bikes, the puller screws into the centre of the flywheel and fits over the shaft, a bolt is then screwed into the centre against the shaft end and the flywheel pops off. If the thread in flywheel looks to be about 26mm then it is the same as the bigger engines so maybe someone at your club could lend you one. ( my gas gas puller fitted my sons mopeds) The best way to undo the flywheel bolt is with a windy gun but if not available, a sharp tap with a hammer on a socket T bar will probably do the trick. Then hopefully there will be something obvious like a broken or loose wire. I have never had a stator issue before but if you can get it off I am sure you could get it tested. Good luck TLTEL Sorry, I had my dinner in the middle of writing that!!! Edited March 17, 2014 by tltel Quote Link to comment Share on other sites More sharing options...
garrym Posted March 23, 2014 Author Report Share Posted March 23, 2014 For those who are still reading this thread... Busy day in the workshop today, managed to concoct a tool to hold the flywheel in place, and with the help of a car jack I could loosen the nut by whacking a socket wrench with a rubber hammer(our air gun wasn't strong enough) and then made another tool to pull the flywheel off . The wires behind were intact but it was filthy, I gave it all a good clean with brake cleaner and the same with the flywheel, put it all back together and got that elusive spark back. Rebuilt the bike, and had to fiddle with the carb, an unrelated issue there, and we now have a fully functional Gasser again, without resorting to either the first aid kit or our local shop. Thanks to everyone for your advice and help. Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted March 26, 2014 Report Share Posted March 26, 2014 Very clever way to get the nut and flywheel off. Awesome that you found the problem and the bike is running well again. It sounds like you had a bad gasket or seal of the housing on that side. Make sure to seal it up to prevent water, dirt etc. from getting in there and fouling things up again. Quote Link to comment Share on other sites More sharing options...
tltel Posted March 26, 2014 Report Share Posted March 26, 2014 Well done for not giving up on it. So you got it running at no cost and learnt a bit more about your bike in the process. Sounds like a good day at the office!! TLTEL Quote Link to comment Share on other sites More sharing options...
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