Spray some carb and choke cleaner around #1. You'll find it pretty quick.

 

Cracked intake boot?

 

What would spraying carb cleaner in #1 do?
I'm going to have to take the carbs off and check the intake boot. I'm just waiting on my float bowl gaskets and jet kit from factory pro.
I did test the compression with a cheap harbor freight gauge tho. They all read 80 psi exactly. The bike ran decently well and pulled pretty hard before so idk about that reading...

 

You're looking for a vacuum leak bro. So you just grab some carb and choke and spray around the carb in place. When the carb and choke gets pulled in, the revs change. Then you just pin point that spot. Super quick, super easy.

 

Also learned the hard way not to put spark plugs in a hot engine.. ended up duct taping a bolt extractor to a ratchet extension to get the broken plug out lol..

 

I traced the line for carb 1 down the side of the bike, past the headers and then can't see where it goes to because the radiator blocks it.

 

I'll venture a guess and say it is vacuum supply for the air injection solenoid.

 

The other end of the line should be connected to the intake boot right below the carb. I think you are tracing the wrong line. Or something is connected wrong. Hose #56 in the attached pic should connect to a nipple on the #1 intake boot (item 1)

 

Maybe something is connected wrong then, because I took the fairings off and traced it to the front behind the radiator 😑 bike is sitting in my garage in pieces rn while I wait for my jet kit and float needles to come hopefully sometime this year.

 

I just took the carbs off and it looks like there's some oil in cylinder 1, should I start crying yet?

 

Na, that looks like guide seals. You'll need a head gasket, a set of valve keepers (16 total, they are sold individually for some reason), a set of valve guide seals, some molybdenum disulfide and some skill. Adjust the valves since you'll be in there anyhow.

Honestly that is an extremely clean runner. Hopefully the rest of the motor looks so choice.

 

2 of the carbs are pretty clean, other 2 are filthy.

 

And the sync lines were routed wrong. Not sure what the hose that was capped with the other vacuum lines is for, so I reconnected them and plugged the mystery hose.

 

In the cylinder or in the intake? The air filter is oiled. You won't necessarily see the same amount of filter oil in each intake. The filter oil however doesn't show up on the spark plugs. Also, if the vacuum hoses were incorrectly routed, consider whether or not that oil may have been pulled from the crankcase breather vent.

 

Intake, where the carbs sit. Oil was only present on that one valve, none on the other 7.

 

Not filthy until the bowls are so full of the solidified green sludge from old ethanol gas that the floats are stuck... those carbs look pretty nice (so far).

 

They were a lot cleaner than I expect for a bike with 40k miles and whos previous owner didn't do any maintenance.

 

omg the no maintenance stuff drives me just a little crazy...

 

The simplest things were never done, some people shouldn't own bikes lol...
But I got my bike running again. Factory Pro jet kit and a carb rebuild from Amazon, synced the carbs and she's pulling pretty good now. I'll take the carbs off again to move the needles up but she runs and I'm happy for now.