A week or so on and I'm still fighting this little hesitation issue right when I first hit the pedal. It only happens if I hit it full. If I ease into it, it's fine. It idles perfectly, and once it gets over the initial low rpm hard acceleration stumble, it's perfect.
Read a ton on vacuum leaks and carbs but every thread I've seen has a little different set of symptoms and nothing exactly like this.
I bought a vac gauge and it's sitting steady at about 16, which is a little low (read 18 when warm would be good). It's is very steady at 16. I've sprayed carb cleaner on every inch of the intake and it does nothing. Sprayed it everywhere there's a connection and potential leak and no change ever. Tried propane too. Nothing. Checked the hoses to booster, dizzy, pcv..all good.
Had Mark rebuild this carb a year ago. It was an 1983 aisin replacement carb for an F and per him was in fantastic shape. It ran perfectly on the old motor.
If I pull the choke about a third out, the hesitation thing goes away but overall it doesn't run quite as strong. I've been pulling the choke 1/3 when I get to stop on a hill and need a solid rev into the clutch so I don't roll back, then I push it back in. All other times I can feather into my acceleration and it's fine.
I also timed and and adjusted the mix screw multiple times per videos and threads I've found. The mix screw is probably about 2 turns at this point but has been in more and out more at various times.
Even replaced the intake/exhaust gasket (2nd one since new motor went in). I was worried about the header and intake not being perfectly flat. The one shop in town who could flatten them is out of business thanks to COVID. I have a jt header and used the thicker gasket...can't recall the name right now.
What about valve adjustment...can't imagine a freshly built motor from an experienced 2F shop would need this right?
Any direction is helpful. Spent the better part of a week trying everything I can and I'm not making any change. It's totally drivable but obviously after all of this it would be nice to get it
right!
