race gas

[fryedaddy]

my engine was running fine-428 yesterday. i put 5 gallons of 110 race gas in it,cranked it,it was fine. got back in it later and it started flooding and the float bowl wont adjust,it just keeps on flooding and it pours out the sight plug no matter if you lower the bowl. could this race gas be bad or just happened because of something else.car did set for 6 or 8 months for other repairs.

[fekbmax]

Needle n seat assembly most likely stuck, clogged or leaking by the o ring .

[machoneman]

Needle n seat assembly most likely stuck, clogged or leaking by the o ring .

Fekbmax nailed it. Replace all the needle/seat assemblies or get Holley o-rings. Do not use hardware store o-rings as few have the exact size or material. What happens is with age and exposure to gasoline, the rings harden and in doing so, shrink. Gas passes right by the now hard and often cracked rings, flooding the carb's well or even passing gas over the top of the fuel bowl.

[Stangman]

X3 on what they said unless carb is fairly new and just a piece of dirt in the needle.

[cleandan]

All of what has already been said is great advice.

But you could simply have a piece of junk stuck in the needle/seat causing it to stay open.

You could remove the needle and seat, blow it out/clean it, and put it back in.

If it was only junk it will now work fine.

But I also suggest you look closely at what type of junk is in there.
If you are running braided fuel lines with rubber liners they do eventually fail and start letting little pieces of rubber hose go and this just turns into an almost constant junk in needle/seat issue until that whole flexible fuel line is replaced.

[Falcon67]

I run VP110 regularly and I have to change the seat assemblies every spring before racing starts.  I don't blame the fuel LOL.  If it's going to sit a while, pull the fuel feeds and spray either WD-40 up there or Fogging Oil to coat the seats.  When running methanol, that's a requirement between races.

[fryedaddy]

i took the n&s out and cleaned it but i did not see any debris. it still flooded after i put it back in and lowered the bowl pretty low.the o ring looked hard and shrunken to me.i will get new parts for it,but the good news is,let me start from the beginning,i bought a 850dp in the 80s ,used it many years happy with it,about 7 years ago it did about whats happening now,so i sold it to a buddy and i bought a new 850.i have not been as happy with this one,its not as snappy as the old one was.after taking it apart several times i was ok with it.i called my buddy yesterday who i sold the old 850 to 7 years ago and he still had it and he had just got it rebuilt.he let me have my old 850 back and i threw it on my car and i didn"t have to touch it.very crisp like it used to be.im going to run it and keep the newer other one for a spare

[Rory428]

You may want to check the float (s) on the old carb, possibly has a pinhole, and taking on fuel, which would prevent it from "floating", which could cause excessive fuel inside the float bowl(s), and cause it to come out the vent tubes.

[fryedaddy]

You may want to check the float (s) on the old carb, possibly has a pinhole, and taking on fuel, which would prevent it from "floating", which could cause excessive fuel inside the float bowl(s), and cause it to come out the vent tubes.

i took a small screwdriver and a flashlight and moved the float  through the sight plug hole and it seemed to be floating and working right,then i took it apart and no gas was in the float. plus this carb is only a few years old,it just sat for about 9 months.i believe its the needle and seat like everyone said. the old carb from the 80s is the good one i just now put on.its the new one from 2017 thats giving me problems

[70tp]

I just had a 600 Holley go dead rich and first thought was needle and seat o rings, changed them out (they were in bad shape) and still rich.   New power valve brought it back around

[fryedaddy]

I just had a 600 Holley go dead rich and first thought was needle and seat o rings, changed them out (they were in bad shape) and still rich.   New power valve brought it back around

mine wasn't just rich, it was dumping gas down into the crank case and would not stay running unless you floored it,but im putting new pv and n&s in it but im using the old carb i got back off my buddy