You explained everything very well, older video I know, I have a problem with my carburetor, it is a 4150 my truck will not start until you prime the carburetor, once engine starts it runs fine, when you turn ignition off you have to repeat process, pumping the accelerater with not get gas to carburetor, also what is diaphragm # or do you sell a kit with diaphragm and accelerater cam to repair carburetor , one of the best videos I've seen on accelerater pump, any information will be helpful, THANKS
William there is several things I would check, first make sure accelerator pump is working properly usually 2 or 3 pumps will be enough to prime it. Other things is weak ignition, bad gas. These are the most common things I can think of right now. Hope this helps.
@@holleycarbshowtosadvice40y90 OK, THANKS, I replaced diaphragm in accelerater pump, ordered parts from Holley to finish. Gasket and new diaphragm spring. Ethanol gas is not good for carburetors.
I've been looking everywhere for good tuning info on my 4150, but have had nothing but conflicting and bad info including from Holley themselves, their videos are particularly terrible. You're videos are amazing and really well explained, can't thank you enough! Maybe my 383 will finally be running perfect soon!
I just rebuilt my 4781 and when adjusting the secondary 50 cc pump clearance for .015 at WOT the other end of the lever between cam has around .100". Is that right?
No John , sounds like you have either a wrong part or a damaged part , the 50cc parts are all different from the 30cc , 50cc pump consist of a different acellerator pump spring , diaphragm, diaphragm housing, accel pump adjustment arm and a different cam , make sure you have all the correct parts . Hope this helps
Great content! Very informative and consistent with information I have gathered from racers over the years. I have a 650 cfm Ultra XP from Holley. It's a great carburetor with TONS of adjustability but the car runs super rich at idle and WOT. Can you do some videos on emulsion and air bleed tuning? I'm definitely going to step down on the idle jets and the PV restriction jets. I'm wondering if the air bleeds will be adversely effected when doing so. The cam is a hyd. roller 234°/242° @ 0.050" 0.530"/0.530" lift 110° LSA. Main jets are 69 front 72 rear. Using front and rear PV's @ 4.5 in of Hg. idle vacuum is 7-8 in of Hg. Thanks Randy. P.S. I noticed 2 HVH carb spacers on you BBC tunnel ram intake. I work at HVH as a Co-op engineering student programming the CNC mills that make those spacers. You sound pretty local based on your accent.
I have several videos out on how to set your transfer slots do this first and then start working with your four idle speed air bleeds maybe go .033 larger on all four. Now before you change the emulsion bleeds if your still rich then tune with the power valve slowly. Usually holley has the emulsion very close on those carbs, but if need be I have a video on the emulsion circuit , always right down where your bleeds are to start with. Hope this helps
lots of help thanks for doing it . can you tell why you have to change the arms and the cam to swap to the 50 cc pump without changing arms. I have been using them for a long time don't really notice any difference.
Check to see if your check valve is stuck . Remove your pump discharge nozzles and use a pick to loosen the check valve, be careful not to open the primaries or the check can come out and drop in your intake , the safe way to do this is with the carburetor off the vehicle this should fix the problem, if not let me know.
@@holleycarbshowtosadvice40y90 thanks the float was just stuck I just gave it a light tap outside what the back end of a wooden screwdriver and it popped up running all good thanks
This guy helped me more in less than 7 minutes more than 2 hours worth of other videos! Thanks man!
Thank you.
Holy cow. Your videos are awesome man. You can explain things far better than those summit guys🤣
Thank you .
Awesome videos!
Thank you
I can already rebuild holleys but ur videos, the tricks & tips has gotten me on top of my game.
Thanks.
very happy I found your videos! Finally starting to fully understand about holley carbs!
Happy to help
You explained everything very well, older video I know, I have a problem with my carburetor, it is a 4150 my truck will not start until you prime the carburetor, once engine starts it runs fine, when you turn ignition off you have to repeat process, pumping the accelerater with not get gas to carburetor, also what is diaphragm # or do you sell a kit with diaphragm and accelerater cam to repair carburetor , one of the best videos I've seen on accelerater pump, any information will be helpful, THANKS
William there is several things I would check, first make sure accelerator pump is working properly usually 2 or 3 pumps will be enough to prime it. Other things is weak ignition, bad gas. These are the most common things I can think of right now. Hope this helps.
@@holleycarbshowtosadvice40y90 OK, THANKS, I replaced diaphragm in accelerater pump, ordered parts from Holley to finish. Gasket and new diaphragm spring. Ethanol gas is not good for carburetors.
Absolutely.
Make sure you can see the accel.pump squirting gas as soon as you move the throttle.
@@holleycarbshowtosadvice40y90 OK, THANKS.
Great videos!!! Very easy to follow and understand. Thanks Randy
Your welcome
I've been looking everywhere for good tuning info on my 4150, but have had nothing but conflicting and bad info including from Holley themselves, their videos are particularly terrible. You're videos are amazing and really well explained, can't thank you enough! Maybe my 383 will finally be running perfect soon!
Good luck bud
Most informative videos
Thank you
I just rebuilt my 4781 and when adjusting the secondary 50 cc pump clearance for .015 at WOT the other end of the lever between cam has around .100". Is that right?
No John , sounds like you have either a wrong part or a damaged part , the 50cc parts are all different from the 30cc , 50cc pump consist of a different acellerator pump spring , diaphragm, diaphragm housing, accel pump adjustment arm and a different cam , make sure you have all the correct parts . Hope this helps
Great content! Very informative and consistent with information I have gathered from racers over the years. I have a 650 cfm Ultra XP from Holley. It's a great carburetor with TONS of adjustability but the car runs super rich at idle and WOT. Can you do some videos on emulsion and air bleed tuning? I'm definitely going to step down on the idle jets and the PV restriction jets. I'm wondering if the air bleeds will be adversely effected when doing so. The cam is a hyd. roller 234°/242° @ 0.050" 0.530"/0.530" lift 110° LSA. Main jets are 69 front 72 rear. Using front and rear PV's @ 4.5 in of Hg. idle vacuum is 7-8 in of Hg. Thanks Randy. P.S. I noticed 2 HVH carb spacers on you BBC tunnel ram intake. I work at HVH as a Co-op engineering student programming the CNC mills that make those spacers. You sound pretty local based on your accent.
I have several videos out on how to set your transfer slots do this first and then start working with your four idle speed air bleeds maybe go .033 larger on all four. Now before you change the emulsion bleeds if your still rich then tune with the power valve slowly. Usually holley has the emulsion very close on those carbs, but if need be I have a video on the emulsion circuit , always right down where your bleeds are to start with. Hope this helps
lots of help thanks for doing it . can you tell why you have to change the arms and the cam to swap to the 50 cc pump without changing arms. I have been using them for a long time don't really notice any difference.
You have to change them because they are different, thats why you put them in as a kit.
if you change low speed air bleed size (idle) , what will that change? Will it make it richer, or leaner depending on the size?
Bigger the air bleed means less fuel they work opposite of main jets
Yes the larger hole will make it leaner and the smaller will make it rich
im not getting ANY fuel out of the primary nozzles..suggestions?...help??
Check to see if your check valve is stuck . Remove your pump discharge nozzles and use a pick to loosen the check valve, be careful not to open the primaries or the check can come out and drop in your intake , the safe way to do this is with the carburetor off the vehicle this should fix the problem, if not let me know.
@@holleycarbshowtosadvice40y90 thanks the float was just stuck I just gave it a light tap outside what the back end of a wooden screwdriver and it popped up running all good thanks