ted630
XS400 New Member
Hey guys. I bought a 1980 xs400 a few months ago, rebuilt the carbs, and i've been riding a little over a month now. After the rebuild it started up with ease every time, though sometimes i would have issues with high RPMs at idle (it will randomly shoot up to 3-4 grand). This was inconvenient, but it was rideable. Today, after 2 days sitting in the garage, it wouldn't start at all. I changed my spark plugs because they were totally black (they were new a month ago) and about a mile into my ride, I came to a stop sign and when I downshifted the bike lost all of its power. I rolled on all the way but it wouldn't go above like 800 RPM and when I rolled off it cut out and wouldn't start back up. I popped the clutch rolling down a hill and rode home, but it felt really weak and tired the whole way back. This same thing happened to me twice before I rebuilt the carbs, but after that I haven't had any issues.
I'm not sure what to make of this. The hanging idle problem is a sign of lean mixture, but the black spark plugs mean it's too rich. Then I replace them and it loses power. Is the mixture the problem? Is it the plugs? or am i totally off the mark?
(note: I'm running NGK BP7ES, and they're gapped correctly)
thanks guys
I'm not sure what to make of this. The hanging idle problem is a sign of lean mixture, but the black spark plugs mean it's too rich. Then I replace them and it loses power. Is the mixture the problem? Is it the plugs? or am i totally off the mark?
(note: I'm running NGK BP7ES, and they're gapped correctly)
thanks guys