I may have done something stupid, white smoke from exhaust By glavey (Read 5,124 times)

[Bashan]

I said don't screw the stick in just to clarify. There are no absolutes on the oil fill amount. Always put some oil in, check it, let it settle, put some more in, let it settle, repeat until up to the top of the crosshatch. That way you know you have the right amount, as I said they vary.

White smoke is gas, blue smoke is oil. See if the exhaust pipe smells like gas right after you shut off the bike. Pull the plug and look at it. Oil comes up through the rings or down through the oil seals. Gas has to come from the intake, make it through the combustion chamber, and out the exhaust. Something is pouring gas down through the head IMO. Alley? Hey Cyborg, you've slapped a few 4Ts together, what do you think?

[glavey]

So I DO have to fill it up to the top of the crosshatch?

I pulled the plug and it is dry, no oil at all. However, as I stated earlier, there is oil spitting out of the crank case venting hose coming from the valve cover, which is connected to the intake which means it will eventually end up being combusted. Perhaps the amount of oil being burned is just enough to produce smoke but not enough to make the spark plug wet.

I will check if the exhaust pipe smells of gas tomorrow.

[Alleyoop]

If it is white it is most likely fuel that is spraying out of the muffler, start Start it up and put you palm by the end of the muffler to get some on your hand and smell it.

I fill my oil and do NOT screw it in to check. When the level is halfway up the xxxxx's it is full. If you then screw it in and check it, it will cover all the xxxxx'x, so your dip stick looks just fine halfway up the xxxx'x without screwing it in.
Alleyoop

[Bashan]

Jul 10, 2014 18:35:19 GMT -6 glavey said:

So I DO have to fill it up to the top of the crosshatch?

I pulled the plug and it is dry, no oil at all. However, as I stated earlier, there is oil spitting out of the crank case venting hose coming from the valve cover, which is connected to the intake which means it will eventually end up being combusted. Perhaps the amount of oil being burned is just enough to produce smoke but not enough to make the spark plug wet.

Alley is going to make fun of me for this next diagram so let's get it all out of the way right now! Don't get obsessed about the amount of oil on your dipstick. It's splitting hairs, what appears to be a lot of movement on the crosshairs is very little vertical movement. OK, go ahead and laugh at my diagram...ahhh...heh...

So if you're up or down a little on the stick don't worry, it's very little real world level change. That doesn't mean let it run down, just don't obsess about it, halfway, all the way, it will work. Are you done laughing now Alley? Can we move on? Thank you.

Your plug is dry because it is gas and not oil. The amount of oil coming out of the crankcase breather is negligible, it will not show up as a combustion byproduct. Take the crankcase breather out of this equation and all subsequent equations. Remove it from the airbox, plug the airbox opening, tie the breather off higher than the valve cover, put a filter on the end of the breather:

What little bit of oil gets up in there runs back down into the case. Any water substances boil off when the oil goes plus 212, and it does.

[Alleyoop]

No laughter here, that is the way it is, the fill port is at an angle.
Good lesson for the ones that do not realize that.
Alleyoop

[Bashan]

You and John gave me a hard time about that diagram before, that's why I said that. But thanks on the concept in any event.

[Alleyoop]

Last time we were in a giggly mood WE IS IN SERIOUS MOOD NOW But don't expect this all the time

[glavey]

Jul 10, 2014 18:44:32 GMT -6 Alleyoop said:

If it is white it is most likely fuel that is spraying out of the muffler, start Start it up and put you palm by the end of the muffler to get some on your hand and smell it.

I fill my oil and do NOT screw it in to check. When the level is halfway up the xxxxx's it is full. If you then screw it in and check it, it will cover all the xxxxx'x, so your dip stick looks just fine halfway up the xxxx'x without screwing it in.
Alleyoop

I smelled the exhaust after letting the engine idle for a little while. It just smelled like exhaust. I did notice that the white smoke only comes out in the upper rpm range (4000+). If I give the throttle a quick twist I can see the smallest amount of smoke and if I put my hand in front of the exhaust white I do that, my hand does smell a wee bit like gas.

Just curious; from what you guys are saying this is gas in the exhaust, wouldn't that make black smoke similar to having an overly-rich mixture?

Also, Bash, your drawing skills are nothing to laugh at. They make mine look even worse than they already are. Why can I model nearly anything but can't draw anything?

[Alleyoop]

That is UNBURNED FUEL spraying out. Black smoke is burning it and you will have a SOOTY spark plug to rich. You may have a weak spark going on.
Alleyoop

[glavey]

Well my spark plug is rather dark-brown/black. I haven't tuned the carb yet because I was wrestling with an electrical issue. Should I try and get everything tuned up before I do further testing?

[Bashan]

Black plug is too much gas. Where's it coming from? Set your A/F according to Alley's method, it's in the Air Fuel board but I'm not sure where. Then if it's too rich bump the needle up one notch. Is the float valve sealing? The BBK is three years old with minimal miles...that's a lot of sitting, just what the float valve doesn't like.

[Alleyoop]

Here is how to adjust your carbs mixture BUT also get a new plug;
Alleyoop

scooterdoc.proboards.com/thread/1499/4ts-carb-tuning

[glavey]

Already have a new plug.

I will get to tuning the carb now that the regulator won't overcharge the battery.

[cyborg]

quite possibly but oil smoke is light white blue and smells like a 2 stroke when 4 strokes burn oil,,,,,,,do you wash your bike often?,,,get water in the exhaust?,,,just saying

[glavey]

I have never washed the scoot or ridden in the rain or when roads are wet.