Black smoke out exhaust when first started

[astrovan2487]

I've been noticing my bike emits a black smoke out the right side exhaust pipe when first started. It gets worse if you give it throttle right away but the smoke completely goes away after about 3 minutes. I've also noticed that it's a little burnt around that same pipe but the other side is clean. The bike is a 2008 FZ6 with about 17,500 miles, Power Commander, and Two Brother's exhaust system. It dosen't appear to be burning oil, the spark plugs are clean and the oil looks brand new. Is this just from the Power Commander running rich or is this a more serious issue?

 

[champion221elite]

Black smoke typically indicates a rich fuel/air mixture. Try unplugging your Power Commander and see if the problem clears up. Power Commanders work by tricking the fuel injectors to spray more fuel per cycle. If the problem clears up, your fuel map might be too rich for your particular engine. Try selecting a different map and retest.

If the problem persists after disconnecting the PC, you could have one or more injectors that are in need of service. A leaking, or plugged injector can dump too much fuel, or dumps it rather than creating a fine mist. Either way, the incoming fuel can overwhelm the available oxygen which results in unburned fuel creating black smoke at the pipe.

 

[ChevyFazer]

+1 on what he said and to add to it, in most cases black smoke is nothing to be worried about, white or blue smoke is a different story. Right now like he said your bike sounds like its running to rich, and being that it's on startup that leads me to think your sparkplugs could be getting pretty dirty and not properly igniting the fuel but as the engine temps increase more of the fuel is being burned. So I would have a look at the spark plugs and also your air filter if your haven already. If your air filter is getting pretty dirty that could also be making your bike run a little rich since its no longer getting the same amount of air to the engine while still getting the same amount of fuel. But running rich is still WAY better than running lean.

 

[Motogiro]

+1 on above posts. I would primarily suspect the power commander with a bad map. Upload the zero map for the PC an see if that helps. That will make no change to fueling and should eliminate the problem if you've got the wrong map loaded. Before any of this disconnect the battery for a few minutes.

Let us know how it turns out.

 

[Marthy]

Mine does the same thing. Don't let your ECU cycle when you turn the bike on to start it. You can either start right away or leave the kill switch off and wait the dash do is thing...

Make things a bit better. If you feel the bike run a bit rich on idle (not easy without a Auto Tune or a wideband sensor) but mine with stock cams I was using -4 in the zero column at idle (1000-1500 rpm) and the bike was still at 13.8:1

Leaning out the zero column just a bit help to remove some of the popping too. Just go a bit at the time...

 

[FinalImpact]

Did I miss something? It does it when cold and not when hot? If it does it on HOT restarts you should also see it when hot and just revving it. If the later is true you need a new map.

If it only puffs black upon COLD start, I may not worry at all if the plugs are clean and the MPG is good. My S2 runs richer (based upon pipe stink) and quits when the stink when warm. Although I never thought about the CAT having to warm before it works effectively so maybe that plays a roll to?

 

[astrovan2487]

It only does it when cold, never on a hot start. Think I mite have it remapped this winter when I have time to take it in to the shop

 

[astrovan2487]

Well I took it to the shop and they think it's something serious like a cracked piston ring or leaking valve seal. I do not think it's that serious but I told them to do a leakdown and compression test and also adjust the valves (it's about time anyways) It's weird about the same time this smoke started happening the bike started going from 47-50 mpg to 37mpg? I noticed that it smokes heavier when given throttle. Other than the low gas mileage and smoking for the first 5 mins the bike is fine.

 

[motojoe122]

Hopefully its not that serious!
Thank you for posting a follow up, and well......keep us posted:thumbup:

 

[beatle]

Could an injector be stuck partially open? This could allow fuel to leak into the cylinder and build up, causing the black smoke at startup. Since the fuel pump is not running the pressure will bleed down enough so that you don't drain the tank, but when it is on, that cylinder will run rich and burn excess fuel, causing your mileage to go down. Might not be enough fuel for you to notice smoke though.

 

[astrovan2487]

Well I called and talked to the tech working on my bike, he basically said the exact opposite of what the other guy had told me the day before. Said he didnt think anything was wrong with my bike and that it was just condensation when first started. They did a dynotune and I'm supposed to pick it up today!

 

[TownsendsFJR1300]

Black smoke, as noted above, is richness, NOT condensation. Condensation will be white... It shouldn't have any visable black smoke, hot or cold...

If it does the same thing when you get the bike back, IMO, I'd un-plug the Power Commander and try the bike without it...

If there is crap in an injector, I'd strongly suggest a treatment of Chevron Techtron. Hopefully that would help dissolve (and it'll clean) any varnish/ crap in the fuel system...

Please post your results and good luck..

 

[Ben_H]

Black smoke, as noted above, is richness, NOT condensation. Condensation will be white... It shouldn't have any visable black smoke, hot or cold...

If it does the same thing when you get the bike back, IMO, I'd un-plug the Power Commander and try the bike without it...

If there is crap in an injector, I'd strongly suggest a treatment of Chevron Techtron. Hopefully that would help dissolve (and it'll clean) any varnish/ crap in the fuel system...

Please post your results and good luck..

I have to agree I am a ASE automotive tech with my own shop. It is running to rich is it hard to start or does it turn right over. Also try unplugging 02 sensor that is what controls the fuel mix could be giving a false reading.