After reading in another recent thread how the magnet in some replacement rotors can be sub-par, I thought about this possible solution to a problem that has plagued me for several months. Long story short: I bought a new rotor from a vendor to fix a charging problem on my 12,000-mile 1980 650. Well, the new rotor solved that problem fine. But shortly after installing the rotor, the engine developed a strange miss, but only when really warm.
Never suspecting that the new part was in any way related to the miss, I replaced the coil and plug wires, which were original. No change. Went through the carbs, three times. Nothing. Switched out the TCI box. Nada. New plugs. Ditto. Checked valve adjustment, spot on. Compression good.
The other day I read a thread about how someone put a small but powerful rare-earth magnet ($2.00 at Radio Shack) on top of the rotor's magnet, so I tried it. Bingo! This solved the issue. I have ridden the bike about 50 miles since then, and nary a hiccup.
As an aside: I wrote the vendor today letting them know that they may have a manufacturing defect in these rotors. I don't know what's going on exactly, but somehow heat affects the magnet's ability to signal effectively.
New guy here, btw, but was around the other site years ago, and have had bikes for a long time. I've had this one for 15 years.
Dave
Never suspecting that the new part was in any way related to the miss, I replaced the coil and plug wires, which were original. No change. Went through the carbs, three times. Nothing. Switched out the TCI box. Nada. New plugs. Ditto. Checked valve adjustment, spot on. Compression good.
The other day I read a thread about how someone put a small but powerful rare-earth magnet ($2.00 at Radio Shack) on top of the rotor's magnet, so I tried it. Bingo! This solved the issue. I have ridden the bike about 50 miles since then, and nary a hiccup.
As an aside: I wrote the vendor today letting them know that they may have a manufacturing defect in these rotors. I don't know what's going on exactly, but somehow heat affects the magnet's ability to signal effectively.
New guy here, btw, but was around the other site years ago, and have had bikes for a long time. I've had this one for 15 years.
Dave