Post by christoph on May 23, 2008 9:41:48 GMT -5
I have basically had this problem for the past three years. It has caused me to rebuild the engine three times and I am at my ropes end. Here's a description of the components I have replaced/repaired/checked.
Stator was rewound by a fellow in Austin who rewinds these things all the time . All the tolerances are exactly what the manual describes.
I have tried various CDI's including one that was definitely working on my friends Sr (as soon as I put it on mine it would not advance).
I have replaced the battery with a 16vdc 47,000mfd Capacitor which was new and works fine.
The bike starts first kick but when I rev it past the 2000rpm line it does not advance I think (and it is hard to tell because of the vibration) that the advance is actually retarding slightly. I had this problem with an aftermarket CDI I put on the bike ( when I revved it past 2000rpms it would actually erratically retard which I think is to blame for the engine overheating and failing the second time I had to rebuild it).
I have replaced the Regulator/rectifier with a Yamaha OEM brand new unit.
I tried taking the Magneto off my friends bike just to eliminate that possibility.
The ignition coil has been check and indicates proper resistance on the primary and secondary windings.
If anyone has any ideas as to why I am having this problem you would end a long struggle with a beautifully rebuilt Sr engine that has been constantly self destructing.
Stator was rewound by a fellow in Austin who rewinds these things all the time . All the tolerances are exactly what the manual describes.
I have tried various CDI's including one that was definitely working on my friends Sr (as soon as I put it on mine it would not advance).
I have replaced the battery with a 16vdc 47,000mfd Capacitor which was new and works fine.
The bike starts first kick but when I rev it past the 2000rpm line it does not advance I think (and it is hard to tell because of the vibration) that the advance is actually retarding slightly. I had this problem with an aftermarket CDI I put on the bike ( when I revved it past 2000rpms it would actually erratically retard which I think is to blame for the engine overheating and failing the second time I had to rebuild it).
I have replaced the Regulator/rectifier with a Yamaha OEM brand new unit.
I tried taking the Magneto off my friends bike just to eliminate that possibility.
The ignition coil has been check and indicates proper resistance on the primary and secondary windings.
If anyone has any ideas as to why I am having this problem you would end a long struggle with a beautifully rebuilt Sr engine that has been constantly self destructing.
