I picked up am 84 VT500 last fall with 25K on the clock, pretty complete and original - needed to be freshened up - seemed to be classic dirty carbs and lots general maintenance neglect...
I've went through and brought all the maintenance up to date, cleaned the carbs, fresh gas, plugs, fluids, etc...but...
I started out this spring and rode about 10 miles - bike ran PERFECT.
All smiles I stopped to top of the tank with non-oxy and it dropped to one cylinder - then came back on, then off, etc.
Seemed like fuel issues - tank vent, gunk, obstructions, etc...however in line fuel filter seems clean with good flow.
Played with it and figured out that my rear cylinder plugs where wet with no spark. It runs and blows fuel vapor out of rear cylinder... I'm getting gas
- To Much? Fouling plugs to no spark condition?
New plug wires - SPARK! Ran good for a couple blocks - cylinder drops out, comes back, drops out...
Bench test coil...seems OK, but I've been done this path before on other bikes and went ahead and replaced the rear cylinder coil with a new Rick's coil...much bright spark!
Ran good for a couple blocks - cylinder drops out, comes back, drops out...doesn't come back (a few miles)
Check - no rear cylinder spark - wet plugs. (was not the coil or plug wires it seems)
Ignition igniter - CDI box (seems unlikely) - back to fuel issues?
I could really use some knowledgeable suggestions help to sort this out ...bike runs great when it runs "right"
My next step is to look at all the electrical connectors and run a few wire continuity tests... the on again off again thing is always (at least for me) a diagnostic nightmare.
At this point I have a very fresh bike - new tires, brakes, all fluid's, clean carbs, rebuilt vacuum petcock, good body work ...can't stop now
I've restored many British bikes over the years, even built a Triton but am pretty new to the nuances of Japanese "modern" electrical troubleshooting and CV carbs.
Thank you in advance for any ideas you may have.
Jim