black smoke coming from pipes

[logan176]

I originally started this topic in another thread but was told that this would be a good place to continue it.

I performed the "hole saw" mod on my shadow spirit 750 and the sound is great. Now, when I pull the choke all the way out black smoke comes from the pipes... a lot of black smoke. The smoke disappears when I push the choke back in. Does this mean that my bike is running lean?

[AirportFF]

Good to see you moved it over here. You'll get more advice here, not buried in the holesaw mod thread. Nav or Machinehead will be stopping in here soon to help ya I'm sure. :happy:

[amazngrace]

Black smoke means it's running rich. But with the choke on
it's supposed to run somewhat rich.

However, if you can easily see smoke with the choke on
you are too rich somewhere along the line !

Second what AFF said, Nav and Machinehead are the guys
to listen to on this one !!!

...ED

[fegs]

Black smoke= reach and it should be reach with chocke engaged as you are allowing more fuel in realtion to air intake. Have you checked your plugs? They can tell you a lot of things if read correctly.

[AirportFF]

Black smoke= reach and it should be reach with chocke engaged as you are allowing more fuel in realtion to air intake. Have you checked your plugs? They can tell you a lot of things if read correctly.


Fegs....tell me you were shitfaced when you typed that........ :no:


BTW...I sent a PM to Nav to check in here and help you out on the smoke

[navillustoo]

logan,
What everyone has said already is correct, the "choke" on these carbs is actually an enrichment circuit. There is no "choke" blade like on many carbs, it is a needle valve that when closed, stops the flow of fuel through it. When opened, it allows fuel to flow through the circuit directly into the air flow through the carb. If your "choke" is out of adjustment, it may be allowing too much fuel to flow. The shop manual describes how to adjust these needle valves for the particular bike they are on, so if you don't have a shop manual, you really need to get one. They are the most valuable tool you'll have in your tool box!
I wouldn't be too concerned about the black smoke unless you are seeing it with the choke off. If nothing else besides the holesaw mod has been done to the bike, you shouldn't have any Air/Fuel mixture problems. I'm not familiar with Fishkill, Ny. so I don't know what elevation you are at. If you are up in the mountains, at an elevation above 3000 ft. above sea level, you may be a little too rich to start with, but if you are below 3000 ft., I don't think you'll have any trouble.

Brian

[logan176]

Nav, I am below 3000 feet and I will check out my shop manual. I noticed that when I only pull out the choke a little (vs all the way) I don't really see the black smoke. I will do some more checking and get back to you guys...Thanks!