Hi all, just looking for solution to my loss of power at high speeds ie 50 - 70 mph, My bike didn't start one day i think its a bad connection from the starter switch to the main wiring loom, as when i turn the handle bars or try to start again it sometimes works.
Then my bike started missing at normal riding speeds, started very sparadically but then more and more especially when bike been running for a while. I checked the plug and swapped it with another one i had and changed the oil while i was at it. Thought it had cured but no it seems to be getting worse. I had a look at the wiring block under the fuel tank and cleaned connections taped a wire that looked a bit sus, and that seems to have fixed the starting issues but not the misfire/ stutter.
any suggestions would be great also could the two faults be linked?. the bike runs fine on idle and low revs.

is the coil breaking down under load?..imho I would start with a new plug..

Not sure what you mean by breaking down, I changed the coil and hit lead and plug tested again then blown a fuse on the ignition side also headlight wire (black) has got welded in bulb connector spade as lights were working ok but since looking at wiring the light was not working not sure if they are liked

Is the replacement coil new or a known working one?

Years ago when I rode z650's the coils could fail and eventually had to be replaced.

The lights are always on with the ignition so I would assume its the same circuit..

yes it is a good coil, thought a fuse had gone but couldn't find it checked all others by eye and then the bike started again, weird but waiting till dry weather before i take bike out as stripped the plastics off to check if still misfiring. it seems ok holding throttle open at about 4000 revs when cold. i keep you posted over the next day or two. cheers nic roc