TOPIC:

.03 is fine.
now arching between carbs and frame? the only thing i can see is the throttle cables. the carbs are rubber mounted on both sides, the only thing that is metal are the cables. i would take a look in the right switch gear on the handlebar.
now i just had another thought. does this machine have rubber mounted handlebars? it is possible some of the electrical stuff up there has a bad ground? i think my 400's with rubber mountes have a little ground strap under the top triple tree.
if that all looks good then start looking with the ignition system again.
last question. is everything electrical wotking on the bike? lights, charging and all that stuff?

Very strange, if the engine is grounded and the frame is grounded, then the carbs should arc to the engine the same as it arcs to the frame. If not, then there is ground problem. Have you measured the resistance from the engine to the frame (with power off)? Also, measure the resistance from the carbs to the frame and carbs to the engine.

Coil primary polarity shouldn't matter. I'm not sure why they are sometimes labeled on the coil.

Bluemeanie wrote:

No electro guy here but sounds like your creating a "ground" with the screw driver?. Check all connections and try again.

ditto,check ground wires and ground to engine case if bike has one;)

Patton wrote:

Possible leakage of current through plug wire insulation to frame.

Could try the water spray test over plug wires in dark garage while engine running. Might see sparks arcing from plug wire to engine or frame.

Plug wires are new--Dyna reds. I tried the water spray and didn't see anything. But garage may not have been dark enough. I try again after the sun goes down.

flht1997 wrote:

.03 is fine.
now arching between carbs and frame? the only thing i can see is the throttle cables. the carbs are rubber mounted on both sides, the only thing that is metal are the cables. i would take a look in the right switch gear on the handlebar.
now i just had another thought. does this machine have rubber mounted handlebars? it is possible some of the electrical stuff up there has a bad ground? i think my 400's with rubber mountes have a little ground strap under the top triple tree.
if that all looks good then start looking with the ignition system again.
last question. is everything electrical wotking on the bike? lights, charging and all that stuff?

The arcing is not ONLY between the carbs and the frame. I was also able to produce arcing between the carbs/engine and engine/frame when bridging with a screwdriver.

The handlebars are not rubber-isolated.

No problems with any electrical equipment. Everything seems to work fine.

loudhvx wrote:

Very strange, if the engine is grounded and the frame is grounded, then the carbs should arc to the engine the same as it arcs to the frame. If not, then there is ground problem. Have you measured the resistance from the engine to the frame (with power off)? Also, measure the resistance from the carbs to the frame and carbs to the engine.

As I wrote above--I DO get arcing between the carb/engine, engine/frame.

Resistance frame-engine is zero. Carb-engine is abt 100K.

Skyman wrote:

... Plug wires are new--Dyna reds....

New Dyna plug wires likely aren't leaking. And probably have good wire/cap and cap/plug connects. But the earlier failed secondary winding ohm test between caps (which later tested okay) might yet indicate a poor wire/coil connect (where the small brass colored fitting is inserted into the plug wire end and pushed into the coil). Are solid core plug wires being used or the resistor (graphite core?) style plug wires? Am thinking the solid wire core offers better chance for a good connection (could be wrong), but wouldn't hurt to double check the wire/coil connection regardless of wire type.

With the fuel tank mounted, it will be difficult to see any spark leakage at the wire/coil connection during the dark garage water spray test. Would also assure plug wire is relaxed as it exits the coil and not being pulled to one side. The Dyna plug wires are usually plenty long enough, and although new, should be routed so as to not contact or wrap around the frame tubes or other metal parts.

Are resistor spark plugs being used (NGKBR8ES)? Have new spark plugs been tried (NGKB8ES) on chance that an internally defective plug could somehow be obstructing the normal arc to ground across the tip (just a wild theory).

My own direct experience with anything close to this problem was feeling an electrical buzz from the petcock lever while riding and turning the petcock onto reserve. New Dyna coils and plug wires cured the problem. So I believe the old oem plug wires were leaking current to underside of the fuel tank.

Good Luck!

Skyman wrote:

loudhvx wrote:

Very strange, if the engine is grounded and the frame is grounded, then the carbs should arc to the engine the same as it arcs to the frame. If not, then there is ground problem. Have you measured the resistance from the engine to the frame (with power off)? Also, measure the resistance from the carbs to the frame and carbs to the engine.

As I wrote above--I DO get arcing between the carb/engine, engine/frame.

Resistance frame-engine is zero. Carb-engine is abt 100K.

Does the throttle cable (or choke cable-if so equipped) run near the coils or sparkplug wires? If I had to guess, I'd say the throttle cable is picking up the voltage from the coils. The strange thing is that the throttle cable is not grounded to the frame through the throttle and handle-bars. That seems unlikely, but not impossible I guess. You mentioned Dyna wires, but I assume the coils are the original Kaw coils? Old coils tend to get microscopic cracks which can leak sparks especially if there is moisture in the air or on the coils.

If it was me, I'd try to slit open a piece of rubber tubing and slip it over the throttle cable near the coils and see if that fixes the arcing at the carbs. If it does, then it's probably time for new coils. Really, either way, if the coils are over 20 years old I'd be looking for new ones. Coils are the only thing that ever got me stranded. It was right after I rode through some rain. Both coils went belly up within minutes of each other (I tried to make it on two cylinders for awhile).

Post edited by: loudhvx, at: 2008/01/06 02:05

go out to the shop after dark fire the bike up preferaby with gas tank off the bike then shut the shop lights off and look for arcing where the coils mount to the frame and any areas where the coil or plug wires are running close to the frame. cracked insulation on wires or coil cases will cause them to arc to the nearest grounded surface.could also be the ignition pick up coils grounding to the engine case.

does the arcing resemble the firing of the coils?
or is it like a ground once and then takes a few min to build up current to arc again.

If its the firing type, remove the coils and wrap them in elect. tape, I would also make sure the plug wire is sealed