3rdgenmaro

iTrader: (9)

I have been trying to learn how to properly tune a carb. I have read through a ton of different things, including sofakingdom's holley tuning sticky.

One thing that has never really been discussed to any real detail is the accelerator pump, the different cam choices for it, and how to properly set it up.

Holley recommends .015" clearance at full stroke. However after reading everything I have, I have realized to not always go by what holley says.

Here is my question. While standing at the carb looking directly at the squirter (engine off), if you were to barely move the throttle linkage, should fuel come out? Im talking a very small movement. I have adjusted and adjusted and cannot get it to where I think it should be.

My carb accelerator pump adjustment has a factory spring on it. I have went everywhere from the factory recommended 0.015" at WOT, to very loose, to very tight. It still appears to me that it takes too much throttle movement to begin to squirt.

I have read all of the theory behind how hit works. Can someone explain to me the best way to set it up?

Also, could it be a cam issue? Currently it has the pink cam. I know that the pink cam is the leanest during the inital 40*, but it should still squirt with very minimal throttle movement shouldnt it?

57kid?

Carb is a Holley 600, 4160.

Thanks

pancherj

It should squirt out fuel almost immediately (even with the pink cam). How old is the carb? I noticed on one of my old 750's that the spring was compressing instead of moving the pump arm. A few washers to shim the spring fixed that. Make sure that isn't your problem.

3rdgenmaro

iTrader: (9)

It is right at 3 years old.

3rdgenmaro

iTrader: (9)

Fixing to go work around on it some. Hopefully I can get it set up correctly.

RedneckNo4

the pump cams can be set however you want with enough tweaking, my S10 has a 650 dp the primary pump is 50cc's and dumps in a fair amount through the whole movement of the primaries my secondary I left as a 30cc and dumps it all in right away works well for me

3rdgenmaro

iTrader: (9)

Well I ended up going with a red pump cam. I shortened the pump linkage bolt all the way until it came off the pump arm. Then I slowly extended it until all play was gone. Moving the throttle it starts squirting earlier and more then it did. Hopefully I have it fixed right. Didnt get to try it out, Ive got a small trans fluid leak I need to find and fix first.