Is it unusual to staighten out the accel pump control arm a little to increase pump shot when you have maxed out the factory engineered ways to increase pump shot. I'm already using the top hole on my Edelbrock which has a .035 nozzle and it still seems to need more.

:hail:IROC-Z

 

Rocky,

Whatever it takes to get the correct pump stroke. The proper method of adjusting choke pull-off on may carbs was to bend the linkage rods, so I guess you thought isn't at all unorthodox.

 

Are you sure you need more pump shot? Maybe you need to try heavier step up springs on the metering rods. My edelbrock acted like it needed more fuel too. I put the accelerator pump on max. Stepped up the springs one or 2 sizes(don't remember) and decreased the size of the metering rods. This gave me about a step and half richer on the edelbrock tuning chart. Engine runs perfect now. If you have an electric choke carb they're jetted leaner then the manual choke carbs outa the box. Just something to try. The tuning kits going to cost you $50 though. Couldnt beleive a few springs and rods could cost that much.

 

That's crazy isnt it? I bought one Friday night. My carb was manual choke out of the box. I have the silver (strongest) step up springs and .065 x .047 rods. Stock, the rods were .071x.047. The richest rod is .062x.052. think I should try that?

:hail:IROC-Z

 

Remember the BIGGER the rod, the leaner since it's taking AWAY flow area from the jet.

Furthermore, the bigger (first) number on the rod is the part throttle/cruise part of the rod. The smaller (second) number is the WOT/fuel enrichment part of the rod.

If the problem is that it gets "boggy" when you nail it to the floor and you've already maxed out the pump shot then you should step down to a set of rods with a tip diameter smaller than .047". I think Edlbrock makes one that's got a tip somewhere around .035, if memory serves. That's the one you'll want unless you want to tear into the carb and install bigger jets.

The "richest" of the above 3 rods (mentioned in the previous post) will likely make the bog worse, since they actually LEAN the WOT mixture versus the other two. It's only richer on the cruise/part throttle part of the rod.

 

Damon,

I'm glad you explained what the two sets of numbers mean on the rods. That makes a huge difference in my understanding. Stock rods are 071x047. Plugs were balck when I changed them so I knew I had to go leaner. I somewhat blindly calibrated to go leaner but still had that stumble on accelleration problem. The last two sets of rods I have put in, the second set of numbers have been higher than stock rods.

I changed the jets from .113 primary and .107 secondary to .110 primary and .104 secondary last Friday. I have a rod that ends in .037. I'll put that in when it stops raining here.

Many, many thanks.

:hail:IROC-Z