Black Smoke from exhaust on cold start

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Oct 24, 2009 | 10:08 PM

09Sftail

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Stage III

Joined: Sep 2009

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Black Smoke from exhaust on cold start

I have a '09 Softail Custom with Screaming Eagle slip-ons and stage 1 air cleaner kit I installed. I took it to the HD dealer where I purchased the bike and had them do the HD Stage 1 download. Ever since when I start the bike up for the first time of the day, or after it sits for several hours (enough for the engine to get cold) it blows black smoke out the exhaust. If you crack the throttle and raise the RPM's it really pushes out the black smoke. After a few minutes it seems to quit and I don't see the black smoke any more.

I don't know alot about EFI systems on bikes but I have been an auto tech for the last 25 years, and this doesn not seem like it is right or good for the bike.

Anyone have any experience with a situation like this or maybe can tell me if it will have an adverse affect on the bike.

Thanks

Oct 25, 2009 | 12:23 AM

genedjr

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Joined: Jul 2007

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From: Colorado Springs

In the olden days, black smoke was valves, blue smoke was rings.

If we follow this your valve seals are leaking a bit and need to be replaced.
...gene

Oct 25, 2009 | 07:37 AM

prodrag1320

Banned

Joined: Sep 2009

Posts: 3,569

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From: deland,florida

Quote:

Originally Posted by genedjr

In the olden days, black smoke was valves, blue smoke was rings.

If we follow this your valve seals are leaking a bit and need to be replaced.
...gene

???? black smoke is fuel,blue smoke is oil.your just a little rich on cold start,if you had a powercommander (or any other tunable system),you could lean it out a bit,but if it stops in a couple minutes when bike warms alittle,i wouldnt sweat it
kirby
vee twin racing

Oct 25, 2009 | 08:36 PM

09Sftail

Thread Starter

Stage III

Joined: Sep 2009

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Kirby

Thanks for the advice. And as far as black smoke being fuel related you are absolutely correct. Too much fuel going into the cylinders ends up going out the exhaust as black smoke. I'll keep an eye on it and make sure it doesn't get worse. I don't have any way of monitoring what the EFI system is doing unlike I am able to do with cars, so you can see why I'm asking.

Thanks again for you quick reply
John

Oct 25, 2009 | 09:15 PM

Razerman

Cruiser

Joined: Nov 2006

Posts: 164

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From: Montana

Smell your oil on the dip stick to see if any fuel is washed past your rings and into the oil.
just a thought.
R.

Oct 26, 2009 | 01:37 PM

ColdCase

Road Warrior

Joined: Apr 2009

Posts: 1,360

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Doesn't sound normal to me.

How has your fuel mileage been? The EFI has richer cold start AFR settings, but a stage 1 download shouldn't affect it much. Does the bike start with less smoke after an overnight or few days rest? If so, maybe an injector is leaking and then the excess fuel dries out overnight.

Otherwise it could be any number of "hard starting" associated problems.

Oct 26, 2009 | 04:25 PM

BVBOB

Road Captain

Joined: Mar 2006

Posts: 741

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From: West Central WI

It is merely the warmup enrichment function of your ecm, which I believe lasts 90 seconds, the amount of fuel added is an afr multiplier table and controled by engine temp, an easily adjusted table with SERT/TTS type tuners. Likely those tables are not exactly correct for your application, really nothing to worry about.