[NoVa-Corvairs] Idle questions

[Frank DuVal]

Your idle is probably too high.

Reduce the idle speed first and see if the problem goes away.

If the speed is high enough to create some vacuum at the ported port, 
the vacuum advance will pull in, advancing the timing and causing a 
speed increase, which makes the ported vacuum pull even greater, all the 
way advanced. Bliping the throttle reduces the vacuum, temporarily 
returning the vacuum advance to minimum advance timing, then it all 
starts over again.

The idle should NOT change when the vacuum advance hose is removed, 
because there should be no vacuum at this hose with the correct idle 
speed. So, no vacuum, no extra air entering carb port.

Yes, the stuck carb is because somewhere along the ownership chain 
someone left off the washer under the nut. The pot metal squishes under 
the nut and fills in around the threads of the stud. Pick at where the 
gap between the stud and the carb top is with a metal pick. Open up this 
gap and the carb will come off. Wiggle, jiggle, and worry off the carb. 
You can make a hole saw looking tool to cut this gap, but I've never had 
to use this on a carb. Usually this tool is reserved for head studs 
rusted to heads.

Frank DuVal


On 9/18/2014 9:18 PM, daniel--- via Novacc-list wrote:
>
> Had some time after work today to tinker.  If you recall, my Corvair 
> runs well when it's out on the road but idle is ridiculously high.
>
> I found that the idle drops to a normal level if I remove the hose to 
> the vacuum advance.  This makes me wonder if the breaker plate is 
> moving (i.e., advancing) at idle.  Shouldn't idle *increase* with the 
> hose removed because a leak has been introduced into the system, or am 
> I just confused?  Suggestions?
>
> I feel like I'm so close to having a Corvair that runs exactly as it 
> should, but I can't seem to get over this hump.
>
> Also, I replaced the bakelite carb gaskets on three of my four 
> carburetors.  Why only three?  Because my right side secondary appears 
> to be fused to the longer stud -- I wish I was making this up, bit it 
> wouldn't lift off (I didn't try to force it).
>
> Thanks in advance (ha!),
>
> daniel
>
>
>
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