Smoking Out of Exhaust

[JAS6377]

So, I've got a 2004 F. It's been doing this ever since I bought it, but I never really thought much about it. Whenever I choke it to warm it up, it starts blowing smoke like a lawn mower. It stops once the choke is off, and it rides and idles fine. It doesn't drink oil, and I cleaned out the carbs last year when I rejetted.

Is this just another one of those idiosyncratic behaviors of my GS, or is it something I should try to fix?

[Janx101]

Smoke?, or just vapour like when car engines warm up on cool mornings? ... Does it smell of anything other than usual exhaust? ..

If it is smoke , bike using oil or anything?

[Wagoneer]

Does it happen even when it's warm? If not, it could be too rich on idle. Then when you choke it, it gets really bad.

If not, then do you leave your bike outside at night? Could be moisture getting into the exhaust just burning off. If it's not burning oil and it's not oil smoke, then it's probably just idling super rich or it's moisture.

[JAS6377]

Nope. It's smoke. It smells like extremely rich exhaust. She doesn't drink oil or anything, which is why I wasn't worried. I have noticed, though, that it bogs down if I try to rev with the choke on. Mayhaps I'm running to rich? I still get after firing in the exhaust (Jardine) on decels, too.

Edit: I leave the bike in my garage. And yes, it does it when it's warm, at least outside. It did it today, in fact. I never use the choke when the bike itself is warm, so IDK about that. I did just switch out my pilot jets this season for one size larger... Freaking carb tuning. It's such a PITA lol.

[twocool]

What color is the smoke?  Blue, black, or whitish gray?

Blue is bad...burning oil...(oil entering the combustion chamber)...but you say it doesn't use any/much oil....Burning oil has its own distinct smell....

Whitish gray is water turning to steam....moisture in the engine/exhaust..  On a water cooled engine it can mean coolant is entering the combustion chamber...but not to worry on an air cooled engine........burning coolant has a sickening sweet smell....

So on a GS this is only moisture burning off...no problems...

Black smoke is too rich mixture.......But with choke (enrichment) "on....you 're gonna get some black smoke....it also has its own distinct smell.....

But black smoke all the time is a problem...too rich...pull the spark plugs and look...if black and sooty it means too rich....best to do after a long ride, when choke has not been used for a long while....


If plugs are black and wet....then you are burning oil..........

Plugs should be a tan-ish, orange-ish, brown-ish color...

Cookie

Nope. It's smoke. It smells like extremely rich exhaust. She doesn't drink oil or anything, which is why I wasn't worried. I have noticed, though, that it bogs down if I try to rev with the choke on. Mayhaps I'm running to rich? I still get after firing in the exhaust (Jardine) on decels, too.

Edit: I leave the bike in my garage. And yes, it does it when it's warm, at least outside. It did it today, in fact. I never use the choke when the bike itself is warm, so IDK about that. I did just switch out my pilot jets this season for one size larger... Freaking carb tuning. It's such a PITA lol.

[Wagoneer]

Have you tried leaning out the idle by adjusting the idle air/fuel mix knob?

[JAS6377]

Yeah... I've been playing with those darned mixture screws for a while now. I can't seem to get it quite dialed in.

And twocool, it's definitely not oil. It looks almost like it's burning coolant, but it's not. That would mean moisture, then?

[BockinBboy]

If you live in a high humidity area, it could mostly certainly be moisture in the exhaust each time you start her up.  The can tends to draw moisture just because of the temperature changes it experiences when it cools off.  If you think it is moisture, check to make sure the drain hole is clear and not blocked or clogged by anything on your exhaust.  Otherwise, I'm not sure what else you can do if its moisture in the can 

- Bboy

[Snake2715]

I forget have you synched the carbs?

That may be why youc ant get them dialed in.

Just a thought.

Valves adjusted recently? Or before the carb synch?

[The Buddha]

Yeah... I've been playing with those darned mixture screws for a while now. I can't seem to get it quite dialed in.

And twocool, it's definitely not oil. It looks almost like it's burning coolant, but it's not. That would mean moisture, then?
[/quote

You may have a partially blocked air passage in the choke circuit.
It may clean itself ... or not. You can try to clean it with air or something, but do not ever try to remove the stupid pressed in tiny little brass things in the air inlet side mouth. That always gets chewed up on removal, and you cant get them. It may be something you have to live with ... Or soak clean the carb in hot hot hot water and a few drops of that yamaha carb cleaner ... I hate soaking the outsides in that crap though, it tends to etch the shiny outside to a grey ... Just ignore it.
Cool.
Buddha.

[JAS6377]

Alrighty. So, I fired it up today at my girlfriend's house to go home, and it did the same thing. No surprise. I rode it home, and tried again in the driveway. A little bit, but not much. I'm thinking it's a mix of running a bit rich and moisture. It was relatively cool outside this morning after a week of 85 degree weather.

A little run down of maintenance: oil was just changed, valves were checked (all within spec) earlier this season, and the carbs were cleaned last season, and popped off again for new pilot jets this season. The only thing I haven't done is a carb sync.

So, I guess my next step is to take some time to do the sync, and grab some Long Boy mixture screws so I can get the carbs dialed in properly, and without headache. And grab a new petcock... My prime connector keeps getting loose...

[twocool]

Moisture or running rich?  That is the question...

Look at the spark plugs for your answer...

Cookie

Alrighty. So, I fired it up today at my girlfriend's house to go home, and it did the same thing. No surprise. I rode it home, and tried again in the driveway. A little bit, but not much. I'm thinking it's a mix of running a bit rich and moisture. It was relatively cool outside this morning after a week of 85 degree weather.

A little run down of maintenance: oil was just changed, valves were checked (all within spec) earlier this season, and the carbs were cleaned last season, and popped off again for new pilot jets this season. The only thing I haven't done is a carb sync.

So, I guess my next step is to take some time to do the sync, and grab some Long Boy mixture screws so I can get the carbs dialed in properly, and without headache. And grab a new petcock... My prime connector keeps getting loose...

[Gorilla]

@bluesmudge also mentioned this on our vashon island run here on sunday. I am going thru a lot of oil though. hopefully we have the same problem and can help each other.

[JAS6377]

So, I'm kind of grave-digging here. But, I've also had quite a bit of after firing through the exhaust. I have a Jardine. I assume this is normal?