Suddenly lean

[Big T]

I went on vacation last week and returned to work on my Fridge project

Suddenly, I can't get the choke down more than 1/2 way, or it stalls

It starts nicely on full choke, then it used to be that you'd push the choke down to about 25% and you could drive away and push the choke off in a few blocks. It had good throttle response the entire time

Now, less than 1/2 choke and it whiffs and dies when you turn the throttle

For the record, it came to me as a racebike with VM29 SBs, velocity stacks and open pipe. I recent got it streetable again and rode it several times and it performed as above

I pulled the stacks and put K&Ns on it and put a restrictor in the baffle. It started well in the driveway like this and had good throttle response as I demonstrated it to my son and his friends

So, I pulled the carbs and checked the jets. All clean, except maybe one pilot. I cleaned them all, cleaned the main jet wells and reinstalled.

I pulled all 4 plugs and verified spark

Now, I've gone from stacks and an open pipe to K&Ns and some restriction. If anything, this should be running rich now.

What could I be missing?

[BigD_83]

I wouldn't expect it from you, but I have to ask, have you run the tank down to RES and not switched it over?

[Big T]

I pit 3 gallons in just before the last trial run

The VM 29s don't have a vacuum port to run the petcock, so I have to use Prime

[BigD_83]

For something to affect the overall running like that, I'd think that it would be upstream of the carbs. It does sound like it is getting fuel starved on the pilot circuit, though.

Bad gas? Chunk of something in the petcock? Tank liner peeling out?