Black smoke from exhaust......

[scharding]

....when my 86 FJ is warm and I blip the throttle, i get black smoke. Is this a rich fuel condition? It also seems to run rough at idle with some backfires from the exhaust. Now when i am riding and I jump on the throttle at lower rpm's, it stumbles for a split second then takes off like a rabbit.

The carbs were all professionaly rebuilt and calibrated last summer, I run a 4 into 1 header with a Super Trapp exhaust and a factory air cleaner .

I figured this is the time to get it fixed so I'm ready to rock when the snow goes!

Thanks,

Steve

[FJ111200]

Black smoke does tend to suggest a rich mixture.
Try turning the mixture screws in a bit. Start off at a 1/4 turn and see what happens.
Don't go mad with it though and make it run too weak. A weak mixture can cause overheating and holed pistons.
Better on the rich side than weak.

[andyb]

Ask your plugs what they think.

[scharding]

Ask your plugs what they think.

I will have a talk with my plugs this week and see what they have to say! Thanks!

Steve

[scharding]

Finally had a chance to talk to my plugs. It seems #1 is a nice golden brown and in good condition electrode wise, now #'s 2 and 4 have more carbon on them and are wet with gas. Now #3 is dry but has more carbon like #'s 2 and 4. All the plugs only have 5000 kms (3000 miles) on them.

so? Any ideas?

I mean, how can you have 3 different symptoms out of 4 plugs?

Steve

[Mark Olson]

Finally had a chance to talk to my plugs. It seems #1 is a nice golden brown and in good condition electrode wise, now #'s 2 and 4 have more carbon on them and are wet with gas. Now #3 is dry but has more carbon like #'s 2 and 4. All the plugs only have 5000 kms (3000 miles) on them.

so? Any ideas?

I mean, how can you have 3 different symptoms out of 4 plugs?

Steve

hmmm, sounds like your blinker fluid is low.

sync your carbs, check the needles for the same setting , are there holes in your diaphragms .

when all else fails , clean your carbs.

[SlowOldGuy]

I mean, how can you have 3 different symptoms out of 4 plugs?
Steve

That's easy; because you also have 4 carbs.

What condition are the carbs in, what jets, how many turns on the mixture settings, and what's the fuel/float level set to?

DavidR.