Carb issues

[sbig]

Well I spent all day cleaning the carb bodies, started with hot soapy water, followed by PineSol, followed by oven cleaner, followed by soapy water again, then blowed out with air, then carb cleaner, air again and poking at various orifices.

I got really lucky. When pulling the choke rods, I knew about the ball bearing detents, but did not think about springs for them, but in hindsight it is obvious they have to be there. During reassembly, I stepped on something on the floor and found a tiny spring. Thought about it for a while.... and decided it had to be for the detents, looked and would you believe spring for #1 was still in the body after hours of washing. So I was lucky twice, first for finding the spring on the floor, and second for not loosing the #1 spring.

Everything is 90% reassembled, just waiting on o-rings for the needle valve seats and the idle mixture screws.

I am worried about the diaphragms, two of them did not line up real well in the grooves.

Carb #1 throttle plate was visibly open and passing light while all the others were against the stops and closed, so I eyeballed it and closed it about the same as the others. Hopefully I'll be asking about carb syncing in a few weeks, as I know nothing about it.

[Larrym]

Tab A in Slot A....

I am worried about the diaphragms, two of them did not line up real well in the grooves.
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Details: The diaphragms do have a "tab" that needs to be placed in the right position in order for it to seal/seat properly:


(Courtesy of Member WildKat.)

Function test of the slides/diaphragm is to lift the slide, cover the proper vent hole in the intake of the carb, and then release the slide. If it stays up then ya got a good enough seal.

[natemoen]

Well it sounds like you sort of got the bench sync idea on your own so that's a good thing. As long as all the butterflys are close to the same when they go back on you should be at a good starter point.

The diaphragm shrink down a little it seems after you pull them out. I smear a little petroleum jelly around the ledge and that seems to hold them in place long enough to get the cover on.

[sbig]

I did have the tab lined up, thanks to the earlier post with a link that showed that. I'll try the functional test.

[SFerinTEXAS]

Bench syc. I use the bright sky looking thru the carbs. Far more accurate than a bread tie.

[James England]

I am worried about the diaphragms, two of them did not line up real well in the grooves.
.

I found the same thing when I did my carb rebuild, using new diaphragms. I found the trick is to put the slide in but then hold it right up, through the mouth of the carb. The diaphragm domes upwards and the ring around the edge will then sit in the groove dead easy. Then you put the spring in and put the carb lid on, keeping the slide up as much as possible whilst you put the lid on. Judicious sliding of the lid from side to side enables you to feel that the lip of the diaphragm has gone into the groove.