Exhaust Smokes After Sitting for a Couple of Days (Honda CB900F)


CB750 Member
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New York City
I have an issue with my bike smoking after sitting for a few days.

If I don't ride my bike for about 4 days when I go to crank it up the exhaust will smoke for a good 3 min or so until the bike is warmed up. (Its a gray smoke not black.) However if I ride it back to back days I don't have this issue with the bike smoking.

My best guess is that I have a small leak around my value seals that drips into my piston and burns off after the bike is cranked. I wanted to ask the board what it else it might be before I go an crack the engine open replacing parts. I also wonder if the values just might need adjusting? I don't think its an issue with the rings since it doesn't smoke while riding.

For context bike has about 29,000 miles, runs great, always has the gas off turned off when I'm not using it, and is stored on the side stand (I removed the center stand to mount my battery)

Thanks for any help
The valve seals ARE a known problem and you have enough miles to be there. Beware common gasket set seals like Athena oe Vesrah, they die faster than ----.
You pretty much have, the rings don't wear that fast if nothing untoward to damage them. Assuming you have not whoppingly overfilled the oil.