Slow Air Valve in Air cleaner body

[Guest]

Hello,
The manual has a test for the slow air valve diaphragm, but there is a second valve within the air-cleaner housing. Is this serviceable? I cannot find any other reference to this secondary valve. The manual states to replace the air-cleaner housing if the slow air valve allows "two pumps of air" to pass. What pressure does two pumps relate too?

I have my carbs off; they have been overhauled and I would like to reassemble. The slow air valve diaphragm holds a vacuum of 18" per the manual but I have no good way of testing the pressure of the secondary value.

Any suggestions or help would be greatly appreciated.

Thanks,

[SIR tricky]

Is this a California model or an 85 LTD (gold).
I dont see any air valve in the air cleaner housing in my 85 Aspy.

Maybe someone with those models can help.

[Guest]

I don't know if it is a CA model, but I know it is not an LTD. I will have to look at the manual again to be sure. It does not have the gas tank canister that went with the CA models.

The value is located within the recessed area under the slow air valve. There looks to be some type of locking ring with slots for a very thick blade screwdirver. When you remove the slow air valve diaphram, you can see a smaller diaphram located within this recessed area. This diaphram is spring loaded. Looking into the carb air housing from the top (when installed) there is a circular standoff around four small holes.

I will try and get some picture of it for all to see.

_________________________________________________________________________________
Here are some pictures of the valve:

[Guest]

Here are the pictures again.
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[William_86]

my bike is not a california model, but i also remember about a member whose carbs didn't had that valve and that was because his bike was not US model. so maybe thats why yours don't have it also (tricky)

my bike is US non CAlifornia model and has that valve

when i did my carbs i cleaned it with lots of gas and it started to work smooth as it was stuck when i pushed it the first time, it has a little spring in there.

[SIR tricky]

my bike is not a california model, but i also remember about a member whose carbs didn't had that valve and that was because his bike was not US model. so maybe thats why yours don't have it also (tricky)

my bike is US non CAlifornia model and has that valve

when i did my carbs i cleaned it with lots of gas and it started to work smooth as it was stuck when i pushed it the first time, it has a little spring in there.

Could be

[Guest]

Hi Owaace,

You're actually testing the operation of that second rubber valve when you check to see if 1) air flows freely through the slow air valve and through the tubes that go to the carburetor, when there is no vacuum on the diaphram, AND THEN 2) the air stops flowing when you put vacuum on the diaphram. Vacuum on the diaphram pulls it away from that second rubber valve and allows it to close.

tom

[Guest]

Tom,

Thanks for the response. When I follow the test procedures in the manual, it states, "apply a few pumps" of the air pressure tool to test the second valve. I do not have this tool, so I am "winging it" by applying air pressure with my lungs. With light pressure, the valve holds, with a stronger blow, the valve "buzzes" as air escapes around the diaphragm edges.

So I really don't know if I have a good valve or a bad one. Hopefully I didn't have a good one, which I turned into a bad one with an improper test.

Brian

[Guest]

Owaace,

Here are my thoughts. But experts might have a fuller opinion. The normal direction of the airflow (without the vacuum) is from the air plenum, through the slow air cutoff valve, and into the carbs via that middle airtube connecting the two carbs of each bank. When there is vacuum on the diaphram of the slow air cutoff, that source of air supply to the low speed fuel mixture in the carbs is cut off. So the fact that with low pressure you are not able to get airflow (while the diaphram is under vacuum) indicates that air won't be flowing to the carbs, which is good. (Hopefully when the diaphram is under vacuum you can't use your lungs to suck any air through that hose you're blowing on either.)

The diaphram is under vacuum when the carb butterfly is closed. Under those conditions the air-cutoff action of the slow air cutoff allows a slightly richer mixture from the carbs into the engine, and this along with the shutdown of the secondary air supply to the exhaust pipes by action of the anti afterburn valve (actuated by the same vacuum) prevents popping in the pipes on deceleration.

Bottom line: I think your slow air cutoff is OK.

tom

[Guest]

Tom,
Thanks for the education. I got the bike running last night and sync up the carbs per other instructions on the forum. The engine runs great!!!!

I did this using a 1/2 gallon lawn-mower fuel tank duck taped above the aircleaner. I am still waiting on a new fuel pump that I ordered from bikeband.. They are usually very good about prompt shipping, but not this time.

So to steal a line from StarWars "It's Working!!!!"
Thanks everyone for the input. This is a fantastic site .
Brian
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