Weak Spark/Plug Color?

[1948man]

Are there situations where you could have weak spark but not a sooty plug to go along with it. My plugs are white (not bone white) and I'm wondering if this tends to eliminate weak spark for a weak feeling. If I richen up by one washer (1/2 groove on Dynojet,) I get a stumble so I don't think I'm crazy lean. With the setup now I accelerate smoothly but it seems weaker than 6 months or so ago.
PS. ape pods, 4 into 1 V and H. stage 3

[BassCliff]

Hi,

Could it be that you're just getting used to all that power?

Have you tried the coil relay mod to ensure 12v at the coils?

Thank you for your indulgence,

BassCliff

[1948man]

Thanks, yes I have the coil relay mod. I recently changed the wiring on my Vetter trunk so that all 4 lights function as both running and brake lights and noticed my battery got a little low right after that. I have changed the lights so that only the outside 2 are brake lights now and have charged the battery. I'll see if that helps the battery. I noticed the bike felt a little weaker than usual and also got only 30 mpg for the last tank. I'm thinking what I am really noticing is less torque from putting a 17" wheel on the rear. It doesn't seem that 6.25% should make much difference but maybe it does. The Suzuki engineers probably had it all figured out in the first place. The bike does feel fine at 60-75 mph. I was thinking that if I did something that compromised an effective spark I should see more color on the plugs.

[Johno]

Are your valves within spec?

A very basic part of the equation but does make a huge difference to the total running of these bikes.

[1948man]

Yes, valves adjusted within past 2500 miles.

[Normk]

A bit of a mis-fire won't necesarily show up on the plugs. The suggestion regarding the coil relay might be worth investigation, however. I imagine that Cliff was speaking generally regarding ensuring that you have sufficient voltage at the coils rather than specifically regarding the relay modification. Have you a test voltmeter with which you can measure the voltage drop to the switch (+) side of the ignition coils?

Anyone who has time should do this check as it will indicate the potential of problems later. A low voltage is usually the clue that some remedy such as the coil relay modification is required. If one is showing a low voltage drop, there will be no advantage to the modification.

Voltmeter + onto the battery + or battery cable side of the starter relay; voltmeter negative onto the switch side of the ignition coils with engine running. You should measure < 0.5 volts. If you are showing 2 volts+ it could be worth jumpering power to the switch side of the coils and trying a test ride to see if the symptom remains.

A low voltage to the coils will result in a weak spark which will typically manifest as mis-firing during cruise and very high RPM.

Any chance you have HID? According to the year, your bike has electronic ignition, right? Given the waveforms when the HID on my 1970 GS850G is switched on, I wonder if the interference just might affect the electronic triggering?

Yes, valves adjusted within past 2500 miles.

[1948man]

Thanks Norm, I have the coil relay mod and have measured volts at the coil by putting positive probe from the multimeter on the hot prong of the coil and black prong to a grounding point on the frame nearby. Before the coil relay mod, the voltage was low but is close to 12 now. I haven't measured the way you suggest and will try that today. The bike felt a little better yesterday after changed the lighting on the trunk a little more so that I only have 2 running lights. I'm thinking of changing those bulbs to LED. Am I correct in thinking that as long as it isn't a bulb that flashes I won't need to bother with a different flasher and do the LED bulbs draw less juice?
PS.. No HID conversion.

[BassCliff]

Hi,

Yes, LEDs draw less current. Yes, if the LEDs are not part of your blinker system you won't need to change your flasher relay. My blinkers and tail/brake lights are all LED. I have a few review videos on my Youtube channel (basscliff6) of the different LEDs that I've tried. Feel free to have a look if interested.

Thank you for your indulgence,

BassCliff

[1948man]

Thanks Cliff, I have ordered a couple of LED's. I have cleaned all my connectors I could get apart (a couple wanted to crack rather than come apart) and the voltage at the + on my coils measures over 12 with the key on. I forgot to check it with the bike running.