MEGALADON

My almost new 600 cfm vac, sec, is puking gas
from the top already. wont idel for long, and will stay running
at 3800 rpm only. I only have 300 miles on it.
whats sticking? my float, some kind of valve. thanks

Brettmc

Stuck float, I'll bet.

Brett

MEGALADON

So now i have to rebuild it
Is there a simple solution

GDaina

just remove the fuel bowls and replace the needla and seat

If you have center hung floats, you don't even have to take the bowls off..unscrew the needle and seat and replace.

MEGALADON

Is that the screw with the thin nut under it on top
of the bowl.

GDaina

Yes, Loosen the screw but secure the bolt with a 5/8" box, then start loosening the nut. Put pressure on the nut as you loosen it, else it will jump the needle and gall the edge.

toddalin

May just be as easy as adjusting the float level. Before you disassemble anything remove the sight plugs and check the level. With the car idling, fuel should just be BARELY DRIPPLING out the holes. If you get a nice steady stream of gas, you're set too high, and gas can and will puke out as you describe.

If the level is not correct, loosen the screw/bolt on the top of the float bowls and adjust the floats so it barely dribbles out.

zwede

If the needle got stuck it is usually possible to free it with a few well placed taps with a hammer. Tap it on the seat on top of the bowl.

Btw... tap it as in "tap it". Not "whack it"...

chevymans 77

You might want to see if the carb has an inlet filter. If not, you may want to add one. Also I am not sure if the 600 has a view port on the side of the bowl to adjust the fuel level but if it does you may want to remove the plug and crank the car and watch the hole to see if fuel flows out. The level should be set to the bottom of the whole. A little fuel may drip out of the view port but it should not run out. If it does run out it is flooding. My experience with holly carbs is they will not tolerate much trash in the needle and seat area.

I am no expert; this is just my experience with Holley carbs.

Neal

MEGALADON

I have no sight glass, just the little screws.
I will try opening one today and see if gas rushes out.
I did the tap on the top, and it worked for about 3 minutes lol.
I will see if i can adjust it before I go buy the needle and seat.
It really must be trash, it has only the internal filter, no external.
I just put a new 305 in my 82 4x4. It has not run since 2000.
so there has to be junk in the carb, from the tank

Wrencher

It sounds like debris is getting in the needle and seat. Make sure it has a good filter, pull the needle and seat assembly to clear it (note the position/adjustment of the seat before you unscrew it), then pull the sight plug and adjust it. Word of warning! You are dealing with gasoline on a fiberglas car!! Many a vette has come to grief amid a fiery death due to carelessness. Keep the gas cleaned up, use tons of ventilation (outside is good) and keep an extinguisher handy. Not trying to scare you, just take it slow and be careful.

Hans

chevymans 77

They make some clear plugs to replace the brass plugs in the fuel bowl so you can see the fuel level without removing the plugs. You should be able to get them at the local auto parts store.

w1ctc

Take the line off the carb and stick it in a clear bottle. Disable the ign so it won't start and turn the engine over. Look for
junk in the gas.
Bob

MEGALADON

I would like to thank everyone who helped here
When i pulled the float out, it had a tiny piece of trash in it.
Its amazing,the trouble it caused. I put a inline filter in also.
this was on my 82 GMC 4x4.