I feel your pain Spare. Most of the carbs I do are Yammies. The jets are much smaller and clog easier. Have you ever messed with F40 carbs. They are an absolute nightmare. The best thing they ever did was to make that motor an efi

I've got a HONDA sitting at the house right now waiting for me to do the carbs. I don't know how bad the YAMAHA's are, but try doing a HONDA sometime. 4 different fuel circuits in them, and they are so small you can't hardly get a torch tip cleaner through the jets to clean em out. Not to mention the whole intake has to come off to do the carbs as the intake wraps around the whole starboard side of the engine block. As for the OP, be careful with those 140 carbs as they are plastic and most carb cleaners will dissolve them to puddy if you aren't careful.

One set is off of a F40. The ultrasonic doesa pretty good job cleaning them, If I think they aren't clean enough, I let them sit in the Yamaha cleaner over night. I just got my new set of sync gauges. I've been borrowing a set, figured it was time to but a set

I still need to buy a set of guages yet, I don't do enough of em to really justify it so I've just been using a vacuum guage. It gets em pretty close, but takes FOREVER.

pro marine has a nice set for a reasonable amount

I really lucked out. My neighbor about 3 doors down used to own a marina. He sold it a while back and offered me some of his special tools at a smoking deal. One of which was a vacumate that I got for $100. Those things are worth their weight in gold. Ferm the Hondas are pretty much the same as Yamahas. We used to be a Honda dealer till Triton got bought by Brunswick. I personally think its easier to pull the intake as an assembly than pulling each carb individually

The best way to isolate possible bad fuel, debris, etc in fuel tank is to hook a portable six gallon tank directly to engine. If it runs fine with portable tank with new fuel then problem is with installed tank, ie, bad fuel, bad hose, primer bulb, anti siphon valve, etc.