QuestionHi Bill,I have a couple of your books and they are great,but I cant find the answer to this one. I was getting no spark at all so I started replacing everything,points plugs,ect.when I put a different coil on the bike and tried to start it the coil started smoking,any ideas? and I still didnt have any spark,Thanks for all of your help,Terr
AnswerTerry, last time someone had a mystery like this, they were checking for spark with used, fouled plugs! Spark was always there, just shorting to ground on the plug electrode, instead of jumping the gap. Sounds like you have that area covered, from your description, though.
Be aware that both plugs must be grounded, when testing for spark. Spark jumps from center electrode to ground on one side and reverses on the opposite plug.
If you used an OEM standard coil (12v, of course), then it shouldn't be smoking, unless it is damaged internally or the points wire is grounded somewhere before it gets to the contact set, causing the primary windings to be fully energized all the time, instead of pulsing via the point set. A shorted condenser can give this effect or a pinched/grounded wire.
You have to start at the beginning: Fully charged battery, then key ON position (first one to the right of OFF, not the one to the left of OFF, which is crank only for the starter motor), check for close to battery voltage at the point contact wire (points OPEN). You should have 12 volts or so there. Be sure that the point faces are clean and shiny. USE some fine emery cloth/fingernail file or whatever to get any corrosion from the surfaces, followed by a spray of contact cleaner to remove all traces of grit and any anti-corrosive coatings. Set point gap at the high point of the points cam. Gap should be about .014" wide. Turn engine over and watch WHEN they open, which should correspond to the F mark alignment on the rotor/stator marks. If adjustment is needed, loosen the point backing plate screws, and rotate the whole plate until the points just open at the F mark. Recheck to see that they are still opening at .014" gap, because moving the plate can change the relationship to the points cam, slightly. When you have a point gap of .014" and they are opening at the F mark (use a meter or 12v test light to check them accurately), then you are done there.
Check for spark with fresh spark plugs, lying up against the cylinder head where the outside shell can ground to the engine. If you have erratic spark, observe the points while you are cranking the engine over. If HEAVY, constant arcing is happening across the points as they open and close, then the condenser is bad or the lead is loose from the points wiring. Unfortunately, the condenser is mounted on the top of the cylinder head cover and can only be accessed by removing the engine. You can do a shortcut and buy an automotive condenser, mount it to a bolt on the camchain tensioner, then splice it into the point wire. Disconnect the wires going up to the condenser and terminate everything at the new condenser lead.
I have copies of Honda's ignition switch wiring, as well as ignition system wiring diagrams, which can be emailed to you. Contact me through my website: www.vintagehonda.com
If you have the Dream Restoration Guide CD, the wiring information should all be in there.
12v-IgnSw-Coil , Coil windings, Coil- wire to point contacts, joined with the condenser (which must be grounded) is the basic flow of electricity for the ignition circuit.
Bill Silver
