Smoke from under exhaust

[Nap]

Hello,

My 05 GS500f was not running well; It would only start, run and idle with the chock on. I did a carb clean and after I put it back together it had the same problems but worse. It would back fire if you applied throttle, the exhaust was very 'puff-puff'y with occasional whitish bursts. The chock had to be on for it to idle and if you applied throttle it'd die unless you immediately released. If you timed it right you could make it to 5-7k rpm, but there was never consistent power-output.

I saw these as signs that it was running lean and took the carbs out and put them back a second time. I didn't really change anything and was surprised that it started to run better again (almost? normal), I assumed there was a vacuum leak that I had sealed. After putting it back together I warmed up the engine and it seemed to be going well. Very occasionally there is a delay in power output when the throttle is applied but it seems hardly noticeable (I have not ridden it yet thought). After the engine was warmed up I was testing the power and watching the RPMs. I noticed white/gray smoke (might be blue, I'm very new to this so I can't say for sure, the smell is... I'm not sure. To me it defiantly smells like something is burning thought.) coming from UNDER (and maybe the side of) the exhaust where the two exhausts merge before going to the exhaust pipe. I think it doesn't start smoking till around 6k RPM. If I let it idle the smoke dies down or completely disappears until I rev the engine again. After I put the bike together and saw the smoke I tried researching what it might be and saw someone mention the carburetor boot clamp might have oil leaking from it if it wasn't tightened. I had forgotten to tighten them, but after doing so the smoke has not stopped. How long would I need to run the bike for for the oil to burn off, and why does it only start smoking at 6k rpm and then go away if that's why its smoking?

My questions for anyone that might know are:
Why is it smoking? How can I, if at all, fix it?
And is it safe to ride? If I can't fix it, what are some peoples opinions about me riding it to the mechanic (10mil away).

Thank you very much to anyone that can help. If anyone would like some more information about what I've done to it or what it's doing besides smoking, please ask.

[Nap]

After looking at it a bit more I think the smoke might be coming from near the manifold where the welding is. It still does not produce the smoke when the rpm is less than 5-6k. I still do not see any white smoke coming from the actual exhaust.

[W201028]

Well nap, Im not sure where to start. Whatever you read about the carb boot clamp leaking oil is incorrect, there should never be enough oil in the airbox to leak from the intake. Its normal to have some oil in the airbox from the valve cover vent, but not a measurable amount.
As far as the leak, if you could take a picture of the motor and point to where you think it is leaking we may be able to help you out. Im not sure if you think its leaking from the exhaust cross pipe, or the ports, or the head gasket. From your description, head gasket may be likely, as higher rpms will blow more oil out. If you want to perform a test, wipe the front of the engine and the pipes very clean, and cover them with baby powder. Run the motor and look for the oil spot to form.

[Nap]

So its been a few days and the smoke stopped. I don't know why it started or stopped but its gone now. I am still having some problems with the bike though. Even with this I'm still not 100% sure why, but now my thinking is that maybe it is because of or amplified by the temperature of the air outside, but even that isn't consistent. The throttle is not responsive some of the time. In first gear its worse I'd say, but occasionally I'll suffer from a large amount of power loss (or a delay) if I don't control the frictionzone and throttle perfectly.