Carburetor question. Bowls not filling back up under hard acceleration

[koko64]

If it's only one bowl giving trouble then I would check that bowl's float valve and needle for an obstruction.
The T piece filter can be hard to spot.
Hopefully your pump  and vacuum lines and hoses are ok There is a list of things to check.
If you cant progress it soon and just want it done asap give it to a carb guy. Make sure the shop knows carbs because in this day of electronic fuel injection many dont get carbs or know how to deal with them.. If you dont mind taking the long slow way in order to learn about the fuel system then the community here can talk you through it.

[ducriderinct]

Koko, there's definitely nothing in the fuel inlet of the carb.

So the fuel pump sends out plenty of fuel. As for the floats, I have no idea what I'm looking yet. I suspect if I go tinkering in there I'm going to break something. How would I go about checking the float valve for an obstruction? Can this be done with the carburetors on the bike?

Which vent hoses are you referring to? The gas tank vent? The gas tank vent hose just go straight down out of the bottom of the tank.

What are you referring to the carb vent hoses? I'm not sure which ones those would be what are you referring to the carb vent hoses? I'm not sure which ones those would be. Are those the ones with the metal coils around them?

They are supposed to go into those little gray airbox things. At the moment the hoses are tucked up above the carburetors in front of the battery.  They were connected to the gray boxes mounted to the frame, I forgot all about those.

Come to think of it, those are only thing that has changed. I had removed them and followed some write ups about routing the hoses up underneath the tank area as others had.

Could this be a cause of this problem?
I tried to find the proper routing for them between the left and right carb and the left and right boxes, but was on able to find any truly specific information on how to route the hoses and where each one goes in relation to the left and right side gray box.

I had reinstalled one box with both hoses going into it, and it didn't seem to make any difference at all

[ducpainter]

Short answer...yes. Those hoses are the diaphragm vents. If they are kinked, or in the free airstream, it can prevent the slide from lifting. If the slide doesn't lift the bike won't pull hard at full throttle. It's like the choke is on because the motor can't get enough air. The plugs should show the bike running rich if that's occurring.

Just make sure they have no constriction, and the routing doesn't allow air to blow directly in to the hoses.

[koko64]

I edited my post.
Checking the float needle requires some dismantling. If its the slide vacuum hoses then that would be a good outcome.

[ducriderinct]

It does pull hard a full throttle, than falls on its face after 2-3 seconds of hard acceleration.

If I hit the gas hard from a part throttle  cruising speed or idle the bike takes off like a rocket and has no fuel issues initially. Seems perfectly normal. Then it seems to me that it sputters like its starving of fuel. Ease off the throttle for 10 seconds or so and hit the gas hard and it'll go like hell again for a few seconds then falls on its face again.  Easily repeatable scenario.

It's sounding more and more like the inlet to the bowl is being obstructed somewhat :/

[Speeddog]

While you're checking, take a close look at the vacuum line that goes from the pump to the vertical cylinder intake manifold.

Those eventually perish, compromising the strength of the vacuum signal.

[ducriderinct]

Ok I'll look at that as well. How involved is checking the needle valve seat and associated fuel paths for obstructions?

[Speeddog]

That's a task best done with the carburetors off.

[greenohawk69]

Don't be afraid to do this task. I just removed and soaked mine for a few days (gunk that gelled in float bowl), cleaned with carb cleaner and then used compressed air. Good now, just need to tune it better. This is new for me.

As has been suggested, if you have original fuel and vacuum lines, while the carb is off, replace them. I did and don't have to worry about cracked lines.

[ducriderinct]

I don't suppose there's any chance of running something like sea foam through the system making any difference in this area, right?

[greenohawk69]

You could try it and see.

[ducriderinct]

Well, I poured some in, and went for a ride. Gonna let it sit overnight and take it out tomorrow to see if it made any difference. If not, I guess I'll be pulling the carbs...

[Howie]

There are filters in those hoses that can clog.  Very rare.  There is also a smaller vent hose that went to the...I think left pod. 

[ducriderinct]

Does anyone have a diagram of how the carb vent hoses are supposed to be routed with regards to the grey frame mounted pods? The carb vent hoses seem to each have a one way valve inline on them. Are these necessary?

[Howie]

They are filters.  Necessary?  I would want them in there.  Will the bike run without them?  Yes. 

They were routed as you have them on my bike, no issues.  They just need to be out of turbulent air