Holley 4160 Questions
Greetings,
First, just want to take a second to thank those who have assisted me in the past. This forum is a great help.
Then, on to business. I have the dreaded leak internally (on my List 3367 carb) and on down to the secondary throttle blades. Seems to be running VERY rich so the leak is likely occurring with the engine running but it definitely occurs with the engine shut down and it will empty the secondary bowl (after 10-12 hours, maybe less time) while the primary bowl still contains a fair amount of fuel. I have read quite a few forum entries and will check the secondary float to see whether it leaks or hangs up inside the bowl........although I doubt this is the problem since the carb empties the bowl AFTER shutdown. I'll also carefully check for warpage or blocked air vents. Any other suggestions beyond those listed above as to possible causes? This problem of VERY poor running came on suddenly and hence I assumed it to be ignition related but later realized that the poor running symptom was virtually identical to the blown power valve issue (not surprising!!). Questions, please:
1.) How long can these engines run with this excess fuel condition before damage to rings/cylinder walls due to the excess fuel washing down the lubricant? On a related issue, when is changing the oil to remove the dilution effects deemed wise? This new engine (not even close to adequate break in miles, yet) was run 15-20 miles with this condition before I determined it was not an ignition issue and started looking at the carburetor.
2.) These torx screws used on the secondary metering plate......would auto parts stores have a screw driver to fit those?
3.) Finally, I think. There seems to be an abundance (at least in my mind) of views regarding the idle mixture adjusting screws on the sides of the primary metering block. Does adjusting these mixture screws alter the amount of FUEL or AIR being delivered to the carburetor internals? At some point in the past I examined a metering block and it SEEMED to me that the circuit containing this needle valve had an entrance inside the bowl at a point ABOVE the fuel level--indicating that it was an air circuit. However, I am far from certain about this. My engine seems to run best with this mixture valve at 3/4 to one turn out rather than 1 1/2 to two turns. Would this indicate an air leak somewhere or a fuel leak?
Thanks for any and all help.
First, just want to take a second to thank those who have assisted me in the past. This forum is a great help.
Then, on to business. I have the dreaded leak internally (on my List 3367 carb) and on down to the secondary throttle blades. Seems to be running VERY rich so the leak is likely occurring with the engine running but it definitely occurs with the engine shut down and it will empty the secondary bowl (after 10-12 hours, maybe less time) while the primary bowl still contains a fair amount of fuel. I have read quite a few forum entries and will check the secondary float to see whether it leaks or hangs up inside the bowl........although I doubt this is the problem since the carb empties the bowl AFTER shutdown. I'll also carefully check for warpage or blocked air vents. Any other suggestions beyond those listed above as to possible causes? This problem of VERY poor running came on suddenly and hence I assumed it to be ignition related but later realized that the poor running symptom was virtually identical to the blown power valve issue (not surprising!!). Questions, please:
1.) How long can these engines run with this excess fuel condition before damage to rings/cylinder walls due to the excess fuel washing down the lubricant? On a related issue, when is changing the oil to remove the dilution effects deemed wise? This new engine (not even close to adequate break in miles, yet) was run 15-20 miles with this condition before I determined it was not an ignition issue and started looking at the carburetor.
2.) These torx screws used on the secondary metering plate......would auto parts stores have a screw driver to fit those?
3.) Finally, I think. There seems to be an abundance (at least in my mind) of views regarding the idle mixture adjusting screws on the sides of the primary metering block. Does adjusting these mixture screws alter the amount of FUEL or AIR being delivered to the carburetor internals? At some point in the past I examined a metering block and it SEEMED to me that the circuit containing this needle valve had an entrance inside the bowl at a point ABOVE the fuel level--indicating that it was an air circuit. However, I am far from certain about this. My engine seems to run best with this mixture valve at 3/4 to one turn out rather than 1 1/2 to two turns. Would this indicate an air leak somewhere or a fuel leak?
Thanks for any and all help.
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