just finished building my guerciotti, and took it for a spin around the block. for it I bought this IRD freewheel: https://harriscyclery.net/itemdetails.cfm?ID=2357

but while riding, I noticed a slight friction pedaling, at first I thought the wheel was rubbing against the frame slightly, it was quite noticeable. But that wasn't it, and the new bottom bracket was super smooth also. What does that sound like to you guys? The freewheel is right out of the box, does it need to be oiled?

When you're pedaling, the pawls in the freewheel body lock-up. The cogs don't move in relation to the body, so there can't be friction.

Maybe the wheel bearings are too tight.

Pedals? hubs? Brakes rubbing?

My. Freewheel problems abounding. If your freewheel is binding, it will carry the cranks around when you spin the wheel in a bikestand. Try it. If the bike acts like a fixed gear, you gotta lube that freewheel somehow.

I once had a freewheel that binded. Turning the rear wheel caused the crank to turn also. Lubed it with grease then oil, loosen the top race, nothing helped. Discovered an extra ball during disassemble, took the ball out and every ran smooth.

it's sorta difficult to explain, you know when you get up to speed, and then you pedal slowly, it feels like there's no resistance? with this, there is a slight resistance, when i pedal forward or backward. i thought it might be the pulleys in the rear derailleur, but they seem to be fine

If your pedal freewheel friction is taken out of the equation.

Coast, if the chain sage along the top side between the freewheel and chainring there high resistenve in the freewheel.

Take your feet off the pedal, if the chainwheeel cmoves as you coast theres very high resistence in the freewheel.

I find lots of old bikes and it is quite often necessary to free up the freewheel. Though I do not use WD40 as a lubricant, it is a good cleaner and freewheel freeeupper.

Remove the rear wheel and rotate the freewheel. Do you feel drag as you spin it? If so, lay the wheel on its side with the freewheel facing up and add a bit of WD40 to the joint, allow the liquid to seep in while spinning the freewheel. You might need to do this a couple of times but do not go crazy with the WD40. When the liquid does its job you will immediately feel the freewheel free up.

Next, add a really light oil to the same joint on the freewheel, again spinning the freewheel slowly to allow the light oil to seep in. I use very light transmission oil for this task. Hope this helps.

Chain in bad condition, not lubed?
Is the chainline bad -- does it tack sideways from the chainring to the freewheel?
Are you used to riding a single speed? Maybe it's typical, normal drag for a multispeed?

nope, neither of these things happen.

I will give this a shot.

nope, new chain, lubed. I'm used to riding a cassette/freehub, so I thought possibly it was just a quality of freewheels, but I don't think so

Thanks randyjawa! Flushed it with wd40, much, much better, and I can actually hear the pawls, I thought it was supposed to be that quiet.

Spray some in a container and see what's left when the propellant evaporates.

Oil.

Its an ok lubricant where thin oil would be used...

i do this with motor oil and it works well, albeit slightly messy since i pour it out of the bottle.