[DeTomaso] Holley 650 problem

[Mikael]

Boyd, a common problem with Holleys

1. Unscrew the needle/seat. Do it like this, and you might not have to
adjust float level, I would still do it though, could be part of the
problem. Loosen the screw 1/8 round max, use a 5/8" to unscrew it
completely. No need to take off fuel bowl or remove carb from engine. Clean
with air. Screw back in, note that gasket between bowl and needle/seat must
be there
2. Adjusting fuel flow in Holleys is not only about jets, that's actually
the last step after float level, idle mixture and power valve are adjusted.
If you're interested, look at my site www.tuningmadeeasy.com
3. If you decide on a new carb, get a Summit 600 vacuum. They have better
throttle response than a Holley, even a double pumper, and they are designed
so you can change jets without spilling fuel all over your engine

Paste from my site:
Float level: "On Holleys this adjustment is very easy as it can be done
without dismantling. With the engine idling take out the sight plug on the
side of the fuel bowl. Be ready with a rag to catch the fuel that might run
out if the float level is too high. With the sight plug removed, use a big
screwdriver and a 5/8"/16mm wrench to adjust (the screw should just be
loosened, adjustment is done on the nut). Adjust so that fuel is up to the
level of the sight plug hole and just slowly trickles out. Note that if the
level is too high and you adjust down, you have to wait until the fuel is
consumed or trickled out, which can be an issue especially on the secondary
fuel bowl. Also note that if you adjust down too low the nut loses its grip
on the float bolt and when you try to get it back up it won't work. In that
situation, stop the engine, take off the screw and nut entirely and screw
the float bolt up with your fingers. You may need a new gasket after doing
this."
Mikael

-----Oprindelig meddelelse-----
Fra: boyd casey [mailto:boyd411 at gmail.com] 
Sendt: 15. oktober 2011 02:01
Til: De Tomaso List
Emne: [DeTomaso] Holley 650 problem

Hi guys. I am having a problem with my Pantera. I have a 73 L with a
Cleveland that has  some modifications. It has a Holly 650 (manual choke)
double pumper, an Edelbrock performer manifold, MSD 6al box, blaster coil
and an MSD 8577 Distributor. I don't know for a fact but I have been told
that it has a mild  upgraded cam , Hall big bore headers and mufflers. Over
the past few days I have noticed a deterioration in the way the engine has
been steadily deteriorating. At first I thought it just needed a tune up. I
bought new plugs but before I could install them the car stalled out around
five miles from home. When the engine died I started checking things out and
I noticed that the rear two barrels of the Holly 650 had allot of liquid gas
sitting in the bottom of the barrels. There was gas still pouring from what
I think are the secondary nozzles , and collecting in the bottom of the
secondary barrels. The car was not running  and in spite of the fact that I
turned off my fuel line ( I have an in line ball cock valve that I turned
off when I saw the gas pouring into the carb.) In spite of my turning off
the fuel supply the gas continued to drip steadily from the nozzles! ( I
assume it was gas that was already in the fuel bowl). I don't know allot
about carbs  but based on my limited knowledge I think it my be a stuck
float. So I am looking for advice.  Should I get a rebuild kit and rebuild
it or should I buy a new carb? If the recommendation is for a new carb
should it be a Holley or something else?  On a side note after I let the car
sit for around
 1 1/2 hours (the engine cooled and a lot of the gas evaporated out of the
carb)  ( I also tapped the fuel bowl with a steel wrench handle in the hopes
that it might dislodge a stuck float )  Luckily I was able to start the car
and drive it home! So please share your advice.  It is my understanding that
Holley carbs require a change of jets to adjust the fuel flow. Are there any
carbs that can be adjusted with a screw instead of changing jets!
Thanks,
Boyd