Unusual ignition problem

 Occasionally, my 1980 Yamaha XS650 will refuse to run above idle (long story
from a previous post) or it will stumble a bit after it warms up a bit, say
15ish miles into a ride.  I can fix it thusly:  pull a plug wire while the
beast is 'running' and then push the plug wire back onto the plug.  May take
one or two tries and it does not matter which plug wire I pull.  New coil,
wire and plug caps.  Other than that, the bike runs like cheap pantyhose and
it starts with a bare nudge of the kickstarter.  Anyone experience such
electrical gremlins before, and if so, what was the root cause(s)?

Here are some pics of the monster
http://webpages.charter.net/clickfam/pictures.htm

Thanks in advance,

Ron

 Ron wrote:

Actually, the first thing I would be checking is the float heights.

 


And related to that, drain/flush float bowls.
Spark plugs.
Carb (intake) boots
Techron or Seafoam in gas

Despite your discovered "fix", this really sounds like a fuel problem.

 
Thanks to all for the replys!

Best regards,

Ron
www.mondo-ron.com