Been so long I can't remember some of the do's and don'ts.

Got a Holley 4bbl on a 351w, keeps losing power slowly at 2800rpm. I can run all day at 2000, but get any higher and it starts sputtering out. I'm thinking the secondary valves aren't opening to let air in and it floods out.

Pulled the carb, everything that I can see looks good. But now to get what I can't. I'm going to go through it with Carb cleaner.

Do I need to dial down the compressed air a bit? I don't want to blast anything apart.

I know this is such an idiotic newbie question, but we lost our newbie section. :D

Hmm... are you sure the secondaries are not opening? I mean, just having the flaps open does not mean you're getting gas if your secondary jets are plugged. I'd get a carb kit for it and rebuild it. Or at least remove the jets and make sure they are clean.

Pulled the carb, everything that I can see looks good. But now to get what I can't. I'm going to go through it with Carb cleaner.

Do I need to dial down the compressed air a bit? I don't want to blast anything apart.

I know this is such an idiotic newbie question, but we lost our newbie section. :D

Not an idiotic question. You're just out of practice with carbs, old man :flipoff2:
Only thing that you can fawk up on a holley is the power valve & the vac secondaries diaphragm. Pull them, and hit that bitch with as much air as you can force through those orifices.

As was already said, make sure your secondaries are opening. Assuming you're talking a vac secondary carb, here, but take and put a zip tie around the pull rod of the diaphragm up against the housing, tight enough that it offers some resistance, but loose enough to be easily moved. Now go romp on it, give the bitch hell. Now look at it again. Zip tie should be down much lower on the shaft. If its not, your back two barrels are not opening, and are the cause of the problem.


Other possibility is that those back two are opening way too much, too quick. If that's the case, put a stiffer spring on top of the diaphragm, and try it again.

if it is a vacuum secondary holley fuel will not flow through the secondary jets with the secopndary throttle blades closed
it is the airflow that draws the fuel out of the booster

take it to a shop that knows how a carb works

buy a big bucket of that chem dip carb cleaner loosen all the fuel bowls bolts (so the chem will get everywhere inside) and soak it atleast 24 hours i usually leave it in 2 days and them disassemble the carb, after soaking use comp. air and small picks, pipe cleaners, and whatever else you may need to clean every hole, valley, clean the sh it out of it then get a holley kit use the blue gaskets (they dont get ate up as bad by fuel, plus you can reuse them)

btw if your out west or up north where they sell e85 you can get a carb kit that is compatable with e85 (may save you some bucks if it is a toy cause i think e85 is cheaper) (we cant get corn juice here...lol).

FWIW the best cleaner I've found for carbs is called marine care, it gets rid of all the green funk and varnish better than anything I've ever used.