Carb slides

[connor1]

Troubleshooting a carb problem on BS38s on a tx frame. Right side carb won't idle steady and stumbles if revved. Took carb off for cleaning the pilot circuit and noticed the slide falls way fast 2 to 3 seconds to bottom out when thumb is over the oval port on top the Venturi.

I have a set of xs2 carbs that I rebuilt and the slide falls in about 10 seconds. So I decided to swap the slides thinking that the diaphragm was no good.

As you can probably guess the "bad" slide worked fine In the xs2 carb body and the "good" slide fell quickly in the carb body I am trying to fix. Yes the choke was closed.

anyone know why this might happen? What will the effect be on peformance if the carb with the quickly falling slide is put back on?

I would swap the carb sets but the choke is a different setup that will cause some other issues...

 

[XSLeo]

On the slide that drops too fast the"choke" which it doesn't have, it's an enrichener, may not be sealing off the enrichener port. The enrichener, when on pulls air from above the diaphram to mix with the extra fuel it sucks from the float bowl and feeds to the carbs.
Poor sealing of the enrichener when closed will let the slide drop fast. Try removing the enrichener valve, it just unscrews out of the enrichener body. Clean the plunger and where it seats.
Leo

 

[connor1]

Spot on as usual Leo.

pulled the "enrichener" plunger and noticed that in the middle of the barrel there is a suspiciously empty groove. Appears to me that this is a good spot for a 1 mm O ring. Now it seals, and the slide drop is 8 seconds. Is that good enough?

Thanks once again!