CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
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Im new to the carb thing... but I've got no idea where to start with this.
I got my new build together and I borrowed a buddy's carb for the initial startup and it turns out my cylinder heads were junk so the car is on stands for a little while.
But I figure I should take the oppurtunity to get to fixin my carb. It's a Holley 650 DP and the squirters (shooters?) are supposed to make a nice cloud of gas over each barrel, right? Mine just sorta drip...
The carb seems like it's in good shape but I have no idea how long it's been sitting and collecting dust before I got it, so I was curious as to what action I should take to remedy it. I've got it apart, but I've seen nothing that my untrained eye would think is an obvious cause for it.
And I have a book on Holleys taht I just read all the way through and it's more about performance tuning that diagnosing problems so it wasnt much help.
Yes a fair amount of gas should come out when you open the throttles to WOT.... SEVERAL cc's.
Check to make sure the pump cam is installed correctly (plastic piece on the throttle shaft just inside the lever where the throttle cable hooks up to); make sure the pump lever is sitting on the cam; make sure the pump lever MOVES when you move the throttle. Correct adjustment of the screw on the lever is such that at WOT, you can still push the lever about .050" before the pump diaphragm bottoms. The screw should be resting on the lever and should move IMMEDIATELY when you move the throttle (no gap or "play").
If all of that is OK, then the problem is internal. If it's a relatively new carb and has the little rubber mushroom looking check valve thing, it's probably got old and dried out. Other than that, about all that can cause the pump not to work, is "foreign matter" in the passages or squirters themselves.
__________________ Numquam ponenda est pluralitas sine necessitate. — William of Ockham, from Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi
Roughly paraphrased into modern English, and applied to figuring out what's wrong with your car:
The simplest explanation that fits all the facts is probably the right one.
Yes a fair amount of gas should come out when you open the throttles to WOT.... SEVERAL cc's.
Check to make sure the pump cam is installed correctly (plastic piece on the throttle shaft just inside the lever where the throttle cable hooks up to); make sure the pump lever is sitting on the cam; make sure the pump lever MOVES when you move the throttle. Correct adjustment of the screw on the lever is such that at WOT, you can still push the lever about .050" before the pump diaphragm bottoms. The screw should be resting on the lever and should move IMMEDIATELY when you move the throttle (no gap or "play").
If all of that is OK, then the problem is internal. If it's a relatively new carb and has the little rubber mushroom looking check valve thing, it's probably got old and dried out. Other than that, about all that can cause the pump not to work, is "foreign matter" in the passages or squirters themselves.
Well we were pulling directly on the squirter cam itself for testing purposes and all it did was just drip gas out. Both sides. So it's not a matter the linkage, we're talking about the squirter itself.
I just took apart one of the fuel bowls to look at it and, again, to my untrained eye it all looked fine. The rubber thing didnt look cracked, it actually looked pretty good to me.
The holes in teh gasket were lined up okay.
I'm betting there may just be some dust in the passages or something. I was looking at it trying to figure out how it works and it seems to me that the whole system is pretty simple to say the least, so it seems like everythign is ruled out except contaminants in it.
carb cleaner with the little red straw that comes with it taped to the side of the can should blow out any foreign matter kyle. just be careful when looking directly at the thing when you blow it out, it'll sometimes squirt back right into the eyeball! i got an eye-full when rebuilding terry's carb...had me crying like a 2 year old in 3 seconds flat!