Any CV Carb gurus? Weird issue with cv carb.

OK this isnt about a motorcycle but the carb is off one. The carb is in a Suzuki Samurai. The carb is new and is a 44mm. This is engine at full temp. It dies when the choke(enrichment valve) is all the way closed but if you remove the choke completely and cap the port it idles and runs fine. I talked to a friends neighbor who works on bikes for living and he said there might be a tear in the accelerator pump diaphragm. You can also see air bubbles coming back into the clear fuel filter after you turn it off and let it sit for a few mins. Anyone else have any ideas?

Since no one has posted I'll provide what limited knowledge I have. The last time I dealt with CV carbs was on a mid 80's Nighthawk S.

First thought is, Has the jetting (pilot, main, and needle position) been adjusted for the Samarai engine?

It sounds like the enrichment circuit is making up for jetting that's too lean.

Second possibility that comes to mind is if the air cleaner or intake boot is blocking a vacuum or bowl vent? Or are the bowl vents capped?

It's possible the bowl isn't venting properly causing a lean condition and the open enrichment circuit is providing a vent.

If you haven't already done it, try running without an air cleaner to see if that changes the behavior, and you'll be able to see what the slide is doing as you close the enrichment circuit.

What brand model carb? CV's are notorious for being a pain to get jetted just right.

44Dwarf wrote: What brand model carb? CV's are notorious for being a pain to get jetted just right.

Its a keihin 40mm strait from harley that has been modified to a 44mm screaming eagle.

Harleys use Kehins? I would have thought Possum Power or All American Carborettor Company or something.

How to tune CV carbs: https://youtu.be/48Ynnsw6lJA

Okay if I'm reading this correctly it will run if you pull the plunger valve out 100% and cap the 10mm hole left behind. If that's the case your pilot system is completely plugged when the plunger is lifted off its seat it opens a port directly to the float bowl allowing the fuel to flow to the engine side of the butterfly. Sudco will have parts and jetting

Sudco

the port that gets uncovered is labeled starter jet on this diagram. cv carb