the artist formerly known as ish Posted September 15, 2005 Report Share Posted September 15, 2005 05 GG 125 pro, running backwards, things tested so far and not worked. All electrics changed over from a known good runner, stator plate, flywheel, also took key off crank shaft and repositioned flywheel on shaft to try change timing still same result, anyone any idea what the cause could be. Could the crank be out of time ? only thing that has not been changed and tested yet ? Quote Link to comment Share on other sites More sharing options...
joe315r Posted September 16, 2005 Report Share Posted September 16, 2005 I had this happen to me on a 1972 Bultaco Alpina. It would only happen occasionaly, but you would let the clutch out, and the bike would go shooting backwards. Very entertaining! Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted September 16, 2005 Report Share Posted September 16, 2005 Will do with points but never heard of it on a modern, spooky Quote Link to comment Share on other sites More sharing options...
alan bechard Posted September 16, 2005 Report Share Posted September 16, 2005 Always done it or did this just start happening? Quote Link to comment Share on other sites More sharing options...
the artist formerly known as ish Posted September 16, 2005 Author Report Share Posted September 16, 2005 Apparently it has AL, some kids bike! not a good situation in point and shoot mode Quote Link to comment Share on other sites More sharing options...
alan bechard Posted September 16, 2005 Report Share Posted September 16, 2005 Could the mounts for the ignition plate be drilled / marked wrong? The case side half. It should be a timing issue, and I would guess that something in the basic setup is wrong. can you see, read, tell when it triggers visually? Then check a known good one for comparison? Do an actual meausurment at the head type reading when it triggers? Do you still have my work e-mail? Quote Link to comment Share on other sites More sharing options...
ahamayfrank Posted September 16, 2005 Report Share Posted September 16, 2005 John, Assuming the bike ran correctly once upon a time: I am not familiar with this particular model but two strokes in general can run in either direction forward or back ward. If the ignition timing is set to fire before top dead center BTDC then it should run forward. If after (ATDC) it will run the other way. With a timing light and the bike running you should be able to see where the ignition is firing. However, you evidently have a bike to Quote Link to comment Share on other sites More sharing options...
brian r Posted September 16, 2005 Report Share Posted September 16, 2005 John, does it do it when it's kicked over, or bump started backwards? The kids Rookie starts all by itself! Pull the clutch in, roll it backwards and it starts. Quote Link to comment Share on other sites More sharing options...
alan bechard Posted September 16, 2005 Report Share Posted September 16, 2005 Frank, I love your sign on name..... Knew who it was the minute I saw it. I think Ish is saying it has always done it from new, and has changed all the electrics, which makes me lean too it may be a manufacturing error in the case half itself. Ish is a dealer, not sure if he handles GG though. Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted September 16, 2005 Report Share Posted September 16, 2005 Good point is that possible? The Bults would run bacwards at anything from about 1.5 btdc, never mind atdc! Quote Link to comment Share on other sites More sharing options...
bullfrog Posted September 17, 2005 Report Share Posted September 17, 2005 I would sure want to hook up a timing light to establish the actual spark timing - regardless of what the timing marks "say". On vintage (points/magneto) systems on a two-stroke, either severely advanced timing (say 30-35 degrees BTDC) or severely retarded ignition timing (say 10-15 degrees BTDC) seem to result in an engine which is more willing to run backwards than a properly timed engine. In my experience, strongly advanced timing often leads to running backwards through the following process: 1) a less than energetic kick brings the piston up relatively slowly 2) spark happens well before TDC and builds enough pressure to reverse the piston travel before it reaches TDC. Voila, engine is running backwards! (with spark timing now @ 30 some degrees After TDC) Ed Quote Link to comment Share on other sites More sharing options...
timp Posted September 18, 2005 Report Share Posted September 18, 2005 Some beta's used to do this a few years ago. Does anyone remember what caused it? Might be a similar problem. Mark T Quote Link to comment Share on other sites More sharing options...
badass76 Posted September 18, 2005 Report Share Posted September 18, 2005 I had a Beta Techno and it started running backwards, replaced the CDI unit and it went as good as a Beta could go! Quote Link to comment Share on other sites More sharing options...
copemech Posted September 22, 2005 Report Share Posted September 22, 2005 Ish, If it has a typical stator plate with 3 screws, be sure it is oriented properly and not 120 deg out of time. All else being correct, the magnet may have slipped in the flywheel causing an incorrect trigger point. That's all I can think of. When are you going to answer my question about the spring? MC Quote Link to comment Share on other sites More sharing options...
copemech Posted September 22, 2005 Report Share Posted September 22, 2005 Ish, If it has a typical stator plate with 3 screws, be sure it is oriented properly and not 120 deg out of time. All else being correct, the magnet may have slipped in the flywheel causing an incorrect trigger point. That's all I can think of. When are you going to answer my question about the spring? MC Quote Link to comment Share on other sites More sharing options...
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