- Joined
- Jul 23, 2011
- Messages
- 47,558
calling all holley carb gurus
Finally splashed the boat this year. however due to budget constraints, I used the 715CFM Holley vac-secondary carb I had. Motor is a 468 BBC with Merlin heads, RPM air-gap intake, Stainless Exhaust with custom pipes
idles great, however needs more on the upper end, and being a single squirter, the hole shot would bog a bit when the secondaries opened if i mashed the throttle
so....fast forward after 30 hours and a few dozen splashes or so on the motor.....time to upgrade the carb.
ebay special, early gen 1 950 HP (date code 3186 - meaning November 13th, 1996) this is just before they went with changeable air bleeds
picked the carb up, discovered the secondary metering block was incorrect for a 4-corner idle carb and the throttle shafts and blades were butchered. mis-matched squirters and an odd staggering of main jets...... i called the guy up to get a refund or make it right. so after getting partial refund
2 new pro-comp billet metering blocks, a Holley /Quick fuel throttle shaft kit and new blades and I have the carb cleaned, painted, and back together
6.5 power valves, #80 jets on all 5 corners, stock emulsion jets in the pro-comp block
now, here is the issue
i can not get the carb to idle.
secondary air transfer slot is showing about .020", primary about .030
idle screws starting at 1 full turn out on all 4 corners
adjusting the 4 screws did nothing
motor will run 2000 rpm or higher, however will not run on the idle circuit
if I sit there with my finger on the accelerator pump and tweek the pump just a bit, i can get it to idle. that tells me its not pulling fuel from the idle circuits
if I put my fingers just above the air bleeds on the throttle horn, I can get the motor to idle.
that tells me that either the pro-comp metering blocks have an issue, maybe with the IFR jets, or there is something else wrong.
the outer 4 air bleeds measure stock at 0.070"
any suggestions?
Finally splashed the boat this year. however due to budget constraints, I used the 715CFM Holley vac-secondary carb I had. Motor is a 468 BBC with Merlin heads, RPM air-gap intake, Stainless Exhaust with custom pipes
idles great, however needs more on the upper end, and being a single squirter, the hole shot would bog a bit when the secondaries opened if i mashed the throttle
so....fast forward after 30 hours and a few dozen splashes or so on the motor.....time to upgrade the carb.
ebay special, early gen 1 950 HP (date code 3186 - meaning November 13th, 1996) this is just before they went with changeable air bleeds
picked the carb up, discovered the secondary metering block was incorrect for a 4-corner idle carb and the throttle shafts and blades were butchered. mis-matched squirters and an odd staggering of main jets...... i called the guy up to get a refund or make it right. so after getting partial refund
2 new pro-comp billet metering blocks, a Holley /Quick fuel throttle shaft kit and new blades and I have the carb cleaned, painted, and back together
6.5 power valves, #80 jets on all 5 corners, stock emulsion jets in the pro-comp block
now, here is the issue
i can not get the carb to idle.
secondary air transfer slot is showing about .020", primary about .030
idle screws starting at 1 full turn out on all 4 corners
adjusting the 4 screws did nothing
motor will run 2000 rpm or higher, however will not run on the idle circuit
if I sit there with my finger on the accelerator pump and tweek the pump just a bit, i can get it to idle. that tells me its not pulling fuel from the idle circuits
if I put my fingers just above the air bleeds on the throttle horn, I can get the motor to idle.
that tells me that either the pro-comp metering blocks have an issue, maybe with the IFR jets, or there is something else wrong.
the outer 4 air bleeds measure stock at 0.070"
any suggestions?
