Sparkplugs Fouling

Hi everyone!

Three years ago I built a Chopper out of my old 1977 Kawasaki 1000 LTD. Ever since I seem to have a problem with my sparkplugs fouling. They last about a week and then the bike begins to sputter and new plugs are in order since the old ones are full of carbon.
Things I did to troubleshoot: checked, rebuilt and adjusted the carbs. I dropped the needles from the factory middle setting one ring down. It bairly ran with this setting. The plugs where white the first day, then fouled slowly again. I checked for sticking choke and everything from the fuel side.
I assume this is caused by weak ignition system voltage since the spark is not the best at the plugs. If I just use the wire against metal, it jumps about 1/2 inch. I tried different (used) coils but it is all the same. I am thinking of getting High power coils to see if this makes a difference.. Does anyone have an idea?
Here is the bike:



More pictures are here: 70chopper.2ya.com/

Thanks for any tips on this..
BTW, I searched through this forum for this problem and did not find anything that I didn't try, from hotter plugs to new points and resistors, measuring voltage from the battery, checking ground to the coils (they are relocated). The power and ground to the coils comes directly from the battery.

Gunnar

Post edited by: 70Chopper, at: 2006/03/10 12:53

Welcome to the site.
Does it run good? Timing can cause fouling, but you'd probably notice the poor performance.
My plugs fouled until I put new coils on. I bought Dyna 3-ohm coils and new plug wires. Plugs have been running tan ever since.
Only problem is that now my pipes are turning blue at the exhaust ports. More fire in her belly, I guess.
Oh... do you use premium gas? If your motor is stock, it should be using regular (87 octane) gas. Some of the un-ignited premium fuel could cause buildup, but that would probably take some time to notice.

ltdrider,

Thanks for the reply.
Yes, the bike runs awesome with new plugs! I checked the timing, manually and with a timing light. It is right on.
I have my eye on these coils:
cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&it...RK%3AMEWA%3APIC&rd=1


ltdrider wrote:

Welcome to the site.
Does it run good? Timing can cause fouling, but you'd probably notice the poor performance.
My plugs fouled until I put new coils on. I bought Dyna 3-ohm coils and new plug wires. Plugs have been running tan ever since.
Only problem is that now my pipes are turning blue at the exhaust ports. More fire in her belly, I guess.
Oh... do you use premium gas? If your motor is stock, it should be using regular (87 octane) gas. Some of the un-ignited premium fuel could cause buildup, but that would probably take some time to notice.

Before spending money on new coils, try measuring the voltage going to the coils. Multimeter needed! Put multimeter in VDC scale, the POS lead on the lug where the wire that powers your coil is connected. Put the NEG lead on the the frame. Turn the key on. The reading you get should be the same as what you read directly at the battery; about 12.4 VDC or so. If less, the coils will not spark sufficiently to burn the crud out of your combustion chamber. Also check the type and heat range of your plugs. They should be NGK B8ES. It is very likely that all new coils will do is lighten your wallet. There is a coil repowering mod in the FILEBASE that covers this topic. Read it and see if it helps if you find your voltage down which I expect you will.

ltdrider,

Thanks for the reply.
Yes, the bike runs awesome with new plugs! I checked the timing, manually and with a timing light. It is right on.
I have my eye on these coils:
cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&it...RK%3AMEWA%3APIC&rd=1


ltdrider wrote:

Welcome to the site.
Does it run good? Timing can cause fouling, but you'd probably notice the poor performance.
My plugs fouled until I put new coils on. I bought Dyna 3-ohm coils and new plug wires. Plugs have been running tan ever since.
Only problem is that now my pipes are turning blue at the exhaust ports. More fire in her belly, I guess.
Oh... do you use premium gas? If your motor is stock, it should be using regular (87 octane) gas. Some of the un-ignited premium fuel could cause buildup, but that would probably take some time to notice.

Coil power modification . Looks interesting and something I might try even though I've not experienced any trouble yet.

- Nate >>

wiredgeorge,

Thanks for the info! I will double check on the voltage going to the coils..
One thing I have to point out though. When I converted my bike to the Chopper, I re-did my entire wiring. The ignition switch feeds now from the battery direcly to the coils. When I measured the leads from the coils I got the same voltage as directly off the battery. I also have to mention that I lenghten the coil wires to about double the size. After I discovered the fouling problem I ran with regular lenght for a while to see if the extra lenght coused the problem.. still fouled after about 5-7 days.. Fact is though that the spark on the plugs is really weak.

I just got done today putting in the coil mod. It starts really fast and I'll take it out in a minute to see if it runs better. It already idles smoother. It was easy to do and well worth the $30 in parts to do it!

70's chopper

In your case (with your new wiring)
I would say check the points and condensor first
Then go for some new coils

Just my opinion though

Also, what voltage are you getting from the battery (and the coils)

If you wired the coils direct to the battery they are probably well on their way to fried. They heat when not out in the air while running the bike. Take the coils off and measure the primary and secondary impedence values and replace the coils using an automotive relay as in the mod I suggested.

I did wiredgeorge's coil mod last week and I can attest to instant starts, faster warmup, and overall smoother running, you may wanna try it if you haven't already.