plug cap needs replaced?

[cros36]

im trying to trace down weak spark issue. ill give the short story and if needed ill bore you guys with a longer story.

5k NGK plug caps.
ohm meter set at 2,000k
one cap gets 005 and the other cap gets 004

ohm meter one step down to 200k
the 005 gets 5.1
the 004 gets 4.7

to me (multimeter and ohms dumb) this seems within limits. i get the same readings consistently.

xsperformance coil Part #17-6810
between primaries i get 3.0 multimeter set at 200
between plug wire terminals i get 013-014 multimeter set at 2,000k

between plug wire terminals seems a bit low, my research shows it should be 015-020. again i dont know if this means anything.

on any ohms setting on multimeter i get no change on multimeter between primaries coil core. the same goes for secondaries and coil core.

plug wires alone are showing no resistance. and coil is bench tested.

im sure im missing a test. and i thank you in advance.

 

[Wolfchen]

Got solid core wire set / universal 4 cyl. kit, $12 at auto parts store.
Stock wires are held in by sleeves / screw-on caps around primary wires & into caps.
Re-Wired primary leads from coils outward to oem NGK caps.
Since NGKs have screw-on outer sleeves cap re-wire job is a piece of cake.
No more lead / cap issues.

I cleaned both coil feed wire terminals & checked for 12+ volts static at the ends - key on.

 

[5twins]

When I install wires into coils and plug caps, I like to trim about 1/8" of insulation off the wire, fan the wire strands out in a radial pattern, then screw it in. I also brush a little dielectric grease on the wire end before installing. I use silicone wire kits for VW Beetles .....

 

[cros36]

so my readings are within limits? seems a little weird that both sides are now getting weak spark at the same time. maybe i dont know what i was looking at and im chasing the wrong problem.

 

[retiredgentleman]

cros36;

With that ignition coil you should have a really good spark. Is the spark yellow or blue? If its yellow, yes its weak. Here's a pic of my spark, which is blue.

Did you by any chance disconnect one spark plug lead while the engine was running? If you did, the high voltage may have burnt a hole through the insulation somewhere in the coil itself. Coil would still ohm out OK (ohm meter uses very low voltage), but the high voltage would be leaking to ground in the burnt area. A device called a megger is commonly used in power plants to check if insulation value has broken down.

 

[XSLeo]

Is the voltage reading at the coils the same as battery voltage? If much less then you will get a weak spark even with all new good parts.
Also on the coil, check for continuity from where the plug wires plug in, to the mount and primary side. Should be infinity.
Leo

 

[cros36]

RG. it looks to me to be yellowish more than blue. there is a difference between the two sides. left side is definitely brighter and i can hear the spark. right seems more weak and cannot hear the spark. and ive been very careful to never let a spark go through without it connected.

xsleo. on any ohms setting on multimeter i get no change on multimeter between primaries coil core. the same goes for secondaries and coil core. i believe this to me infinity.

with your other test with checking voltage at the coil.
key turned on i have 12.25V on the battery
volts to the coil
one primary is 11.80v
other is 1.45v

also, there is around .30 less volts between what i get at the battery, and what i get at the solder point on my pamco on either red, or green.

im guessing that i have a break in the wire somewhere between the pamco and the coil? would this be correct? im trying to learn here.

 

[XSLeo]

The ohm reading for the secondary to mount should read the same as not touching the meter leads together.
The voltage drop is probably a weak connection, A broken wire would be no voltage.
Often the contacts in the key switch and/or the engine stop switch.
If your using the stock switches they can be taken apart and the contacts cleaned.
It may also be weak connections on the fuses. The stock fuse holders are 30+ years old.
One easy check would be to run a jumper from the battery positive straight to the joint where the Pamco and coil hook to the bikes harness, the red/white wire. This will bypass all the wiring between the battery and ignition.
Test the spark with the jumper. Don't leave the jumper hooked up very long, just to test. Too long and the coil will over heat.
With the Pamco you can take the rotor off, remove the pin and slip the rotor back on, leave the nut loose so you can spin the rotor by hand. This lets you test for spark with out turning the engine.
Leo

 

[cros36]

i cut the wires back and splayed them like 5twins suggested.
i thought about the other primary being so low. i realized that it was because the circuit being open. so i pushed the kicker a little bit and im getting 12.3ish on one and 12.4ish on the other. my battery is at 12.4ish so the coil is getting good power.
i turned some of the lights out in the garage and i seem to be getting decent spark. i cant tell if its blue or not. i can hear it on both sides now though.

The ohm reading for the secondary to mount should read the same as not touching the meter leads together.

this is what is happening.

Often the contacts in the key switch and/or the engine stop switch.
If your using the stock switches they can be taken apart and the contacts cleaned.
It may also be weak connections on the fuses. The stock fuse holders are 30+ years old.

new switch, but i will for sure look into this. i know new doesnt mean anything. and no kill switch. new fuse block from napa. but im getting good power to the coil so im guessing that all these parts are working fine.

taking that pin out and testing spark that was much easier.

no stock switches.

my last thought of the day is i can easily start my bike cold, take it around the block and such. turn it off, and then it wont start. bad coil is all i can think of.
i get the same readings at the coils after its been running. i will try the jumper test tomorrow.

 

[Tomterrific]

Do you mean you can start the bike with the enrichening circuit (choke) but as soon as you turn it off the engine won't run? That signals blocked idle jets. The most common fault with old bikes.

Forget about the ignition and give us some symptoms that point to the carbs.

 

[cros36]

Do you mean you can start the bike with the enrichening circuit (choke) but as soon as you turn it off the engine won't run? That signals blocked idle jets. The most common fault with old bikes.

Forget about the ignition and give us some symptoms that point to the carbs.

no i mean that i can start the bike in 1-2 kicks, let it warm up, take it around the block, turn it off. go to start it and get nothing.

like yesterday, it starts first kick after getting my coils put back on. let her idle for 4-5 minutes doing some blips, idle returns great just like always. shut her down for maybe 2 minutes. 2 kicks starts right up perfectly again. shut it down, take her off the lift, get my stuff on, start it up again 1-2 kicks. take it around for maybe 5 minutes, stop to get some gas and it wont start for nothing. pushed her home. got in the minivan, went to school, come home a few hours later, go in the garage, and bang starts right up. let her run for a bit. shut her down. kick it to life again, let her run for a few minutes. shut her down. take some voltage readings, everything is checking out good. go to start it again and get nothing.

since its already story time on here ill keep going.
LAST saturday i went on my first 200ish mile ride. lots of back roads, about 80 mi. on the expressway. lots of stops for directions, gas, stretches. i noticed that it was a little more difficult to start hot, maybe 6-7 kicks, but it always fired up. the next day i go to school on the bike. about 6 hours later i go to leave and get nothing out of her. minivan her home. take carbs off. pilots are good, mains are good. check floats, everything seems good there. then i retorque my head, adjust cam chain, adjust valves, clean unipods. cam chain a bit loose, valves a hair loose. and then that is pretty much where im at now.
my plugs are black as shit after running a bit. gassy when it wont start. so its getting gas, and at least has spark. i do not have a compression tester besides my thumb that get thrown off the spark plug hole. im gonna go through my carbs again and work my way through the little passageways. check over wiring, taking my time on the grounds.

i cant get over the feeling that its the coils because it running good cold. and once it warms up i get nothing.
maybe i should try to run it and keep it running on some new plugs and see if it quits on me?
but im also starting to think my jetting is off, but it has been fine for a few weeks and a few hundred miles.


pamco
green monster coil
good new agm battery
stocking charging system working good!
new auto fuse block.
35/35 headlight
trailer style taillight.
5 ohm plug caps
unipods.
autolite 63 gapped to .035
ill check on my getting.
no airleaks at carb manifolds
open exhaust

 

[Noidea]

I know this is 6 years later and you may not be on here anymore but if you are did you ever figure out that it was the coils or not? Same situation with me pretty much starts up fine rode around the block than I turned her off when tried to kick it it wouldnt start up again.