My 1200ST has developed a bit of a problem!
I parked it up in the garage in November, hooked up to a CTEK charger. I had to use the charger on a car in storage a few weeks ago, so the ST stood 'disconnected' for a while. On starting it last week, the battery was very slow....after a few attempts, it started, albeit running very rough, with popping from the exhaust as I closed the throttle. It eventually seemed to sort itself, although the tickover didn't seem as smooth as previously.
The battery's now fully charged. Yesterday, I decided on a run out, so fired the bike up.....started easily, seemed to tick over fine. As I backpedalled off the drive, it stalled, with no input from me! On restarting, it was coughing and spluttering, but after a bit of revving seemed to clear itself.
On the (short) run, it didn't feel right. On a steady throttle, I could feel a 'small' misfire, the pickup wasn't like it should be....and when I cracked the throttle open, it reached around 4k revs and then there was a misfire (I assume) bad enough to make me think the brakes had self-applied!
Anyway, I rode home....slowly....and started fiddling. With the engine ticking over, I pulled the low-tension feed from each stick coil in turn. The bottom left one had no effect on the running at all, the other 3 were really noticeable when disconnected. So, I'm assuming the one coil has gone.
Do my symptoms fit one coil going kaput? The huge misfire (if that's what it was) surprised me, as I expected the other coil to keep the engine running, albeit not as efficiently as it should.
Any observations anyone?
Pete
