question regarding pilot jets

does it make a difference on the size of ports in the pilot jets? and if so, what effect does it have on carb operation?

Yes, the size of the hole in a pilot jet matters. The larger the hole, the more gas, relative to the air supply is provided to the pilot, that is, idle circuit. More gas richens the air/fuel mixture. If the correct pilot jet isn't selected, the idle mixture will either be rich or lean.

jccwall wrote:

does it make a difference on the size of ports in the pilot jets? and if so, what effect does it have on carb operation?

Does "size of ports" refer to the central bore throughout length of the jet OR to lateral holes bored through sides of the jet?

Am thinking the lateral holes govern metering of air combining with fuel in the pilot jet whereby the pilot fuel mixture is created.

And believing all holes in the pilot jet, central bore and laterals, are very precisely sized and shaped to afford a specified fuel mixture.

This is why wire cleaning of the pilot jet holes may damage the size and/or shape of the holes. Such damage is often very hard to see and likely to adversely affect both quality and delivery of the pilot mixture.

The cure for me was new pilot jets.