Leaderboard

The CR9EH-9 plugs are the right heat range for your bike, having regular coils or COPs makes no difference. Maybe the COPs just got too hot. On a trip a few years ago one was riding a frankenviffer where the original coils were relocated, sitting very close to the rear headers. In very warm conditions the coils would overheat makeing the bike stumble and even stall at some point. After putting a bit more space between the coils and the headers all was fine. Was it only the COPs on the rear cilinders that caused the stumbling?