Author Topic: Plug colors (Read 3401 times)

PeteSC · « **on:** September 09, 2005, 03:45:48 PM »

My B12 has been sitting a while, and wouldnt' start, so usually I go ahead and put new plugs in....after trying to start it with 'suspect' gas.

OK. What does this mean?
#1 Pretty black, and oily.
#2, somewhat like #1, but maybe 2/3's as bad
#3 and #4, pretty clean, not fouled, no oily crap. Looked good.

Changed them out, anyway....bike is running well.

I use the Autolites at $1.29 each, so it's not big deal to throw new plugs ins.....

B12Teuton · « **Reply #1 on:** September 09, 2005, 04:12:28 PM »

Could be anything from a carburation issue to valve adjustment to piston/rings.

If it were a 2 stroke I could tell you more

If you are sure the carbs and valves are good, do a compression test.

PeteSC · « **Reply #2 on:** September 09, 2005, 05:01:40 PM »

It is getting close to a valve adjustment.

I've actually hardly put any miles on the B12 since I bought the DR.

It was running rough at the rally, and I didnt' ride much.
I don't think I did my usual new plugs this spring.

Red01 · « **Reply #3 on:** September 09, 2005, 07:01:49 PM »

What Manny said.

Keep an eye on oil consumption, it you start using, it could mean something more serious.

If you notice any blue smoke, try to note when it smokes. Smoke on hard acceleration usually means the rings aren't sealing well. Smoke on decell usually means valves/guides.

jfudo · « **Reply #4 on:** September 09, 2005, 08:17:21 PM »

If you aren't smoking, then it is probably gas on your plugs instead of oil. Wipe it off and smell it. You should be able to figure out from the smell and texture.

My guess is you have a fouled plug (hard to imagine with a $1.29 plug that has been there for 2 seasons

), and the black oil is really just sooty gas. After that, check to make sure your #1 carb is still functioning properly, like the float bowl isn't stuck.

jwalters · « **Reply #5 on:** September 10, 2005, 11:28:33 AM »

I found this page to be of help. I am not sure if I have seen it here on BA before, but it gets passed around a lot on sohc4.us forum. Anyway, its a nice chart, that people might want to refer to if they are having mixture issues. Apologies, if this is already in the FAQ somewhere, but I get my bike forums confused sometimes

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html