dirty spark plugs

i pulled my plugs out yesterday and a few were dirty. does that mean that i need to adjust my carbs? is the mixture too rich or something?

"dirty"? what colour? were they wet?

Dirty, as in sooty? That means you have incomplete combustion. It can be caused by an inappropriate air/fuel mixture at one or more rpm ranges which correspond to circuits within your carburetors, it can mean you are using the wrong spark plugs, it can mean you are using the wrong grade gasoline, it can mean you have poor voltage at your coils and a wear spark and it can mean your valves need adjusted.

wiredgeorge wrote:

...it can mean you have poor voltage at your coils and a wear spark and it can mean your valves need adjusted.

WG, how do you test to see if you have poor voltage at the coil? I read your article on the relay fix, but is there a definitive way to test to see if this is needed?

There is an easy way to test but you will have to buy a multimeter. They sell them at Harbor Freight for under $5. Put the multimeter on Voltage DC in the lowest scale. The look at your coil. The wires from your ignition are generally black and green with black being for the 1/4 side and green the 2/3 side. The OTHER wire (not spark plug wires) is the power wire. It is generally red, pink or yellow red. Anyway, put the POS lead from the multimeter (RED) on this lead where there is some exposed metal at the coil. Put the NEG (black) lead on a bit of metal on the bike's frame. Turn the key on. MOST older bikes will show about 10 to 11 VDC with the bike not running. Of course, if the bike has sat for a long time, you will want to measure the voltage at your battery terminals as well to ensure you don't just have a low battery. If you have under 12VDC, then the coils will NOT fire as hot as they should. The reason for the lower voltage is the loss in the path to the coils... While it is possible to clean all this stuff and replace some of the corroded bits, it generally isn't all that effective compared to doing the coil mod.

wiredgeorge wrote:

MOST older bikes will show about 10 to 11 VDC with the bike not running. Of course, if the bike has sat for a long time, you will want to measure the voltage at your battery terminals as well to ensure you don't just have a low battery. If you have under 12VDC, then the coils will NOT fire as hot as they should.

WiredGeorge, I ran the test with my multimeter as you described, and I get 12V at the battery, and 11V at the coil. Would you say that doing the relay mod would be worthwhile?

Absolutely - The coil powering mod is definitely called for with 11 VDC measured!

Skyman but PLEASE start your OWN thread for issues related to your bike. Not sure whatever happened to the original poster but this is his thread... The evil practice of asking questions not related to the original poster's questions is call THREAD HIJACKING and is discouraged because it causes confusion in the event the original poster comes back and asks more questions about HIS bike...

wiredgeorge wrote:

Absolutely - The coil powering mod is definitely called for with 11 VDC measured!

Skyman but PLEASE start your OWN thread for issues related to your bike. Not sure whatever happened to the original poster but this is his thread... The evil practice of asking questions not related to the original poster's questions is call THREAD HIJACKING and is discouraged because it causes confusion in the event the original poster comes back and asks more questions about HIS bike...

Sorry, I was just taking off on your comment about having weak coil voltage as a possible cause of the OPs problem. I thought asking for more details might also help the OP. Next time I'll start my own thread. :blush:

Not a problem. I was speaking as a moderator.

I wouldn't get bent out of shape about dirty plugs unless the bike runs poorly or fouls out the plugs more than once a season. If they are new plugs just clean them and pop them back in.

Peter