#3 misfire when cold

[OldVet66]

If none of the other suggestions work consider the petcock. I have an '80 tank on my bike and a problem developed with number three cylinder being cold on startup and kicking in later to run fine until the next cold restart. It progressed to being worse and then number 4 cylinder started doing the same thing. It made absolute no sense until I went to drain my tank and fuel would not flow on prime. Replaced the petcock with a K&L from Z1. Problem solved. The petcock they sent looked exactly like the factory petcock and the box said nothing about K&L. It was manufactured in Japan.

[carpetbagger]

I got the exact same petcock. My original was toast, prime didn't function and gas found its way into the vacuum line. Replaced it when I did all the other intake side work. I haven't even been able to get any more work done yet, and now riding season is done where I'm at.