Bonneville America Forums Forums Technical Forums General Tech Diagnosing Intermediate miss

Over Memorial weekend I rode 300 mi. stopping only for fuel, bike ran great.
Next day started bike was missing after warming up ran fine just puttin around town and countryside ran about 1 hr.
Monday rode home a few miles from home started missing, continued till I parked it.
Started bike today put a spark tester on, both wires tested good spark seemed to be the same to naked eye. All connections seemed to be good. Didn't go for test ride due to T,storms. Earlier this spring I put dielectric grease on all connections.
All I can think of is coils or igniter, leaning toward igniter due to not being consistent or temp related

All suggestions on what to check is welcome

It's a tough one.
I'm dealing with something very similar right now . Bike just started missing on the left cylinder occasionally. Always when I start it after it's been sitting for several hours. After about ten minutes, it starts to fire and runs fine.
I've switched the coils, checked the gap on the pickup coil, still misses on the left cylinder only. Checked for spark, nada.
Just finished checking out the connections on the igniter. They seem clean and after plugging it back in it hits on both cylinders. Sometimes that can reestablish the connections if they're oxidized. If it does it again I'm afraid that it'll be the igniter, about $600 .
I'll do some more intensive checks this weekend.
I need to be sure before forking out that much dough.

Allow me to preface my response with: I'm no mechanic.

I had the same intermittent issues for a couple days, until I realized the Squirrel Condom, on the left carb had fallen off...I know it's a simple observation but that's what my problem was. After I got that replaced I noticed I was still having some missing in the left cyl. took off the carbs and lo and behold the pilot was completely blocked with the main slightly obscured.

Also, I had a Honda VT500C and the moment the carbs went off balance and the engine was warm she would act the same way. I simply needed to balance the carbs every couple weeks.

Like I say, I'm no mechanic, but those were my experiences.