All these responses are good but I'll bet AAAltered's is correct. I have several old YMC Tech Bulletins addressing plug fouling, mainly on RDs but other bikes also, that spoke about weak coils and bad bullet connections. They recommended removing the bullet connectors and soldering the ignition harness wires together to ensure a good
connection and replacing the RD 250/350 coils with XS 500 B coils. (They have the same mounting studs and just bolt in place.) Another bulletin spoke to replacing the high-tension leads even though the current leads appear to be in good shape. Apparently, voltage could be lost through radiation or conduction as resistance through the tested leads was normal.
Lyn Garland
connection and replacing the RD 250/350 coils with XS 500 B coils. (They have the same mounting studs and just bolt in place.) Another bulletin spoke to replacing the high-tension leads even though the current leads appear to be in good shape. Apparently, voltage could be lost through radiation or conduction as resistance through the tested leads was normal.
Lyn Garland