Mod 2: The “Gray wire” mod is now the “Blue/White” (Sky blue for everything other than USA) wire mod. I looked at the wire schematic and found the best place to cut (or pill) the wire is at the CDI unit. The CDI unit has three connectors; you need the connector with three wires. Look for the wire that changes from blue/white to sky blue going to the CDI. Pull out the blue/white wire out of the connector and fold it back into the conduit then electrical tape or silicone it in order to water proof it. This is a good idea if you won’t to change it back to factory or servicing. The second reason is that it will not interfere with the starter circuit at all.
Again, funny. My 2007 WR450F had a GRAY wire which I removed from the connector.
You could probably make your own stuff like this guy. Seems a little easier to just go to your local Yamaha
dealer and plop down the $40 for this kit. As to blocking off the exhaust
port, I used a short piece of 5/8 inch house and stuffed a cut off bolt in it and clamped it up. However, I will be making one of those plates and installing that as suggested earlier in this thread. The only reason I didn't do it to begin with is the Yamaha
dealer did not have new gaskets yet, and I didn't want to render my bike inoperable for a 40 cent part.