Holley 4160 secondaries a bit wet..

[overthepond]

Hey guys,
Just a quick question here,my holley 600 is running a bit wet on the secondaries,well its pooling up in the venturi's to such a point where its leaking from the throttle shaft at idle.
Could this be a duff sec/diaphragm on its way out..?
No other problems as such.
Thanks.

[VileZambonie]

I would adjust the fuel level in the carburetor first

[overthepond]

Good point vile,
I'll get onto that and see if it helps..Thanks.

[blast]

If it is still leaking after you check the fuel level, check for wear/play in the shaft that holds the butterflies.  I've had a couple holleys that had severely worn shafts and would leak out the sides.  It's possible to change those shafts, but the butterflies can be difficult to remove without stripping the screws, they are tight. 

[overthepond]

If it is still leaking after you check the fuel level, check for wear/play in the shaft that holds the butterflies.  I've had a couple holleys that had severely worn shafts and would leak out the sides.  It's possible to change those shafts, but the butterflies can be difficult to remove without stripping the screws, they are tight. 

Another good point but this carb is tight,but i'll check anyways just to eliminate it from the problem.
thanks.

[overthepond]

OK,float is just fine,fuel sits just on the verge of flowing out at idle and no major play in the throttle shaft,one thing i did notice is the sec/diaphragm sounds a bit crinkly when actuated manually (it don't feel smooth when plunged) so maybe its gone a bit dry and it looks to be the original judging by the screw heads on the cover.

Would it be worth investing in a quick change kit along with the new diaphragm purely to ease fitting  ?
Thanks..

[joesgarage71]

If it is still leaking after you check the fuel level, check for wear/play in the shaft that holds the butterflies.  I've had a couple holleys that had severely worn shafts and would leak out the sides.  It's possible to change those shafts, but the butterflies can be difficult to remove without stripping the screws, they are tight. 

 The throttle body can be drilled, bushed, reamed and reuse the old shaft, The throttle shaft blade screws are staked in and can be removed painlessly if you grind the ends off first.(dremel)
 Steve

[overthepond]

Picked up a new diaphragm and compared it to the original.
Looks pretty sick..i noticed where the spring sits that its been sitting to one side,would this cause the secondaries to bind a little causing the diaphragm to twist the way it has done.

[overthepond]

Ok heres a new one..

Now the holley wont lean out on the idle mixture and the blazer can be started from cold without a choke which is not right being as i am in the uk.
The plugs soot up in around 15 min and its warming the motor up too quick and it stinks of gas from the tailpipe.
Mixture screws are non responsive,no vacuum leaks,no gas leaks,all gaskets are new holley brand,power valve,float height correct, new etc etc.
I tried a friends 600 which has exactly the same setup as mine and his ran the way it should,got me wondering if this carb is a dog from new..?
Any suggestions other than getting another q'jet..silly of me to sell the one i had but we all do it...

[TexasRed]

Can you screw the mixture screws all the way in and it not die? Did you miss a check ball for your accelerator pump? Are you sure the gasket for the power valve is seated correctly?

[VileZambonie]

Either you are overfueling from an internal leak or need to jet it down.

[overthepond]

Ok..the mixture screws will go all the way in without it dying but i do get a slight difference in exhaust tone maybe 1/2 a turn before they the start to resist.
Primary jetting is stock from the box 66,tried going down to 62 but no difference.

Vile,where would the carb leak internally,my thinking is the secondary metering plate,the casting looks rough.?

[TexasRed]

Is petrol still pooling up on the secondary side? If so, then that's where it's probably at. Otherwise, it sounds a lot like a powervalve failure.

[overthepond]

No the pooling stopped after i fitted the new diaphragm oddly enough,could the powervalve still blow out even with the blow out protection.
I never thought to check with my carb having it from the box.

[TexasRed]

well, how old is the holley? the diaphragm may have gotten old and torn without being blown out. It might also have a opening point that's too high for your engine ( I doubt that).