What does an exhaust leak cause...?

So going by the idea that my exhaust might be leaking, since I can't seem to track down my engine noise (no, not valves- I know those are all in spec and can tune out that sound)

I thought it might be cam chain, but I checked the chain when I did shims and it was tight, also did the auto-tensioner help out trick to make sure.

Lots of folks saying exhaust leak @ the head sounds like chain/valve train noise.
So it is possible... I know to check with a piece of toilet paper on a stick, but I have to wait till I get in a wind free shed to do so.

My question really is - what does an exhaust leak cause as far as the motor. Other than noise

Would it cause a lean condition? Could it cause engine sync/colortune to be off or not react right?

When I hit my brake REAL hard, as I let up I hear a clunk, almost snap noise.
I have a bad notch in my steering neck bearing, but I don't think that is it.
No play in wheel bearing either.

 

an exhaust leak will cause a lean condition.
(less restriction = more airflow, more airflow without more fuel = lean.)
I'm not sure but i think it would have to be really bad to cause a seriously lean condition.

Not sure about the noise after breaking. I'm assuming it's the front brake. Look for something getting hooked as the front end dives maybe?

cheers
k

 

Yeah, it clicks hard when it comes BACK up. Not on the push down.

Honestly, could even be inside the forks... might be clicking from bottoming out.
I have air pressure in them - so they hold air. Not sure about the oil though. Haven't gone that far yet.