1983 vt 500 honda shadow. Replaced both head's. Starts fine has good power. Yet it pop's or back fires some times after giving it progressive fuel. What do you think. Thank you!

Dis-connect the negative connection from the the top of the motor and check for corrosion. The bike with not fire if it isn't getting a good ground. I have a 1983 750 shadow would not start dumped a lot of parts into it before I found the corroded connection.

The fuel filter is in the tank on the petcock and is self cleaning. I suspect you have bad spark plug caps on your bike the cap is part of the wire. If you remove the wire and take a reading with an ohm meter, the cap should read 5000 ohms . Anything above or below and you should replace the cap. This is probably causing the slight miss.

Your honda shadow 500 over heats,because the oil cant room around the engine of the bike.the problem is the worn out destroyed oil seal .Check and replace the oil seal of your bike.

Hi,
Your valve clearances should be:
Intake .08-.12 mm (.003-.005 in)
Exhaust .12-.16 mm (.005-.006 in)
I usually start all gaps in the middle of given specs, then fine tune from there.
Hope this helps