Exhaust (not smoking but smells really bad) KZ650

how often should i do that ?
a few fill ups?

I generally use the seafoam yearly on my boat. One tip, don't start the bike in your garage with the seafoam. It will smoke when you add that stuff. I have to think that this smell is not engine related if it really smells like diesel. If it were blowby it would be the characteristic oil smoke. If it were ignition, or carburetion it would be missing or running rich and thus smelling of gasoline. Do you have a dead mouse that make a home in your muffler?

no mouse lol when it warms up outside Ill try to get her started and smell some more..

X2 on the seafoam....That stuff is great!
Is your exhaust freshly painted? that could put out a wierd smell sometimes.

naw old exhaust abd about to start a full rebuild and new mac exhaust

New oil.... Is this when the smell started?

Through the clutch view port, what's the oil look like?

Smoke out the exhaust?

Possibly running a tad rich?

Oil leaks anywhere thus oil burning on the exhaust?

Would you by chance have a leaky petcock? I had one leak without knowing and the crankcase filled up with gas. Have you smelled the oil to see if it smells like gas? If this is the case you will washout the cylinders of all lubrication. And the exhaust will smell real bad