PCM 351 Holley Carburetor Help Please This is a little long but I really am looking for help!
DanWard
Carburetors. I've got a 1986 Southern Skier with a 351 PCM with the original
Holley Carburetor. This boat has been very trouble free up until last
summer. Last summer the accelerator pump diaphragm started leaking. I could
only get the diaphragm as part of a rebuild kit and thinking that if the
diaphragm went bad it was probably time to rebuild the whole carburetor.
I'm not a master mechanic by any stretch of the imagination but I usually do
OK. Back in my hot rod days I rebuilt a couple of chevy 350's, I usually
handle most of what comes up on my Harley, my wife's Kawasaki, lawn mower
valve job, etc. I've learned over the years that I have at least as good a
head on my shoulders as the fella working for the shop that I'd be paying
$50.00 an hour. And it seems now a days that just because you pay somebody
doesn't mean they will fix it right the first time. So I felt I stood a good
chance at rebuilding this Holley myself.
So I open the rebuild kit and I was a little disappointed at the minimal
instructions in the kit. There was an exploded diagram that sort of matched
my carburetor. The instructions said to disassemble in numerical order and
reassemble in reverse order. That I can do!
After the rebuild last year things worked great. I had a little bit of a
rich idle problem but nothing that kept me from skiing. But when I got the
boat out for this season the slightly bit rich problem has become a
seriously rich problem. When you look in the venturies in the primaries you
can see gas drip drip drip at idle. I also notice the exhaust smells real
rich. I messed around with idle mixture screws. They seemed to be very
functional. I screwed them in until I could hear the idle speed fall off and
then backed them back off just until the idle picked back up (approx 1/2
turn). This didn't help. Actually they wound up just were they were before I
adjusted them. I then noticed that after I shut the engine off I'd get a
few drips, not a stream but a steady drip drip drip. I suspected the primary
floats were not shutting off the needle valves until fuel pressure was bled
off. But why?
So I called around. I'm in the Houston area and thought that since I tried
once at rebuilding the darn thing and obviously I tripped in my knickers so
now it was time to pay somebody to do it for me. I called Palmer Power as
they are the original manufacture of the boat. They had a 4 week waiting
time (gees that is prime ski time down the drain). So then I called Kiaser
Marine. They wanted almost $350.00 to rebuild it for me. That seemed quite
high as the rebuild kit sells for $50.00 and it only took me, a none skilled
individual, 4 hours to rebuild it. I shopped around some more but nobody
really seemed interested but these first two places. Everybody has more work
than they can do.
So I then priced a new carburetor and found prices ranged at almost $500.00.
Man the American dollar doesn't buy much these days. I just can't justify
the cost of a new carburetor.
So I regroup. Before I can spend $350 to $500 dollars I figure I'll try one
more time to rebuild it my self. It really isn't rocket science. There just
aren't that many moving parts. I go back to Palmer Power and purchase my
second rebuild kit. I take great care this time to insure each and every
nook and cranny is clean. Each and every passage got cleaned thoroughly and
blown out with air compressor. I installed new needles and seats. I checked
float level. This carburetor don't have the external adjustment for float
level. Other carburetors I've worked on in the past there where screws in
the side of the float bowls that you removed and with the engine in a flat
level position you would adjust float level via external adjustment screws
until fuel would just trickle out of where I removed the screws. This is not
the case with this carburetor. This one you put the new needle and seats in,
install the floats, invert the bowl and adjust until the bottom of the float
is level with the bottom of the bowl when held upside down. I'm right on,
they are as level as I possibly could get them.
I then installed the new power valve. I also took great care with the
metering block. You could have eaten off of it it was so clean.
To make a long story a little shorter when I was through reassembling the
carburetor I felt I had done a cracker jack job. I put it back in the boat
and it sprang to life the first time it turned over. I watched for the drips
in the primaries and didn't see a thing. I turned the engine off and watched
again, no drips. I started it back up and adjusted the idle mixture screws.
The thing was idling like a top. I was really feeling good.
I then went to the river last weekend and things worked fairly well. I had
it idling in gear a little to slow as this was something I couldn't check in
the driveway. But no drips and the exhaust smelled much much better. Not
nearly so rich. If I was to complain about anything I might on occasion have
to pump the accelerator to get her to fire off. But being I was coming from
a condition where it was so rich that it would load up and barely crank
through I was feeling good. We actually motored ourselves back to the
trailer when the day was done. This felt great as the two previous weekends
it would get so rich that it wouldn't start, I'd end up draining the battery
fighting the rich problem, and end up getting towed to the trailer.
Now this weekend we go back to the river. The thing is running great and we
beached for a while. After drinking a coke and allowing the dog to swim for
a while we got back in it and it started up, idles for a few minutes,
stumbled, and died. I tried to restart it and the same thing happened that
happened before the second rebuild. It loads up, get really hard to crank
through, and never fires up. I pull the plugs and they are wet with gas. I
sit back and vent a little frustration. Wait about five to ten minutes while
I put the plus back in and then when I try to start it it fires up. I put it
in neutral and fast idle at about 1100 to 1200 RPM. I take the spark
arrestor off the top of the carburetor and look in the primaries. And again
they are drip drip driping. I mean the gas was almost splashing out of the
venturies in the primaries in surges. The same darn thing as before. Once
you put it in gear and start running things are fine, it just will not idle.
Obviously my lack of experience is causing me to repeat my errors. Whatever
is wrong I'm doing the same thing each time I rebuild it and each time it
turns out wrong. I'd gladly pay to have this thing fixed but 4 weeks?
$350.00?
Does anybody have any idea what the problem is? Can anybody suggest a shop
in the Houston area that might be able to fix this before summer is over and
without me having to sell my wife to pay for it? Any and all help is
appreciated. Thanks in advance!!!!!
Doug Meredith
means that it is getting past the inlet valve, that the float should
have closed when the bowl is full. This can be caused by garbage rust
etc, causing the valve to not seat all the way closed. If you have
brass floats, it can also be caused by a small leak in the float which
doesn't allow the float to close the valve, therefore allowing fuel to
sneak past at idle. One other problem that I have personally had is
if you have a secondary metering block instead of secondary jets, and
you either don't clean off all the old gasket, use the wrong new
gasket, or when you don't tighten the screws all the way that hold the
block in place (they have unique heads) it will bleed fuel past, and
allow the carb to flood at idle. Several books that I have found that
are excellent on Holley carbs are the book by Mike Urich, published by
HP books, about carbs and manifolds, and FI. You should be able to
get it at a local speed shop, or I know that they are available at
Barnes and noble online at www.bn.com.
Doug
"DanWard" <Dan...@ix.netcom.com> wrote in message
news:8lfseo$ba2$1...@slb6.atl.mindspring.net...
Rob Cail
the same day !!!
Phil
I've had occasions when my Holley has done what you describe. I remove the
needle & seat, never actually see anything there, replace it & all's fine
till next time, (which is often months or all season). and I've got good
filters etc & can never determin where the rubbish has come from.
Phil
DanWard wrote in message <8lfseo$ba2$1...@slb6.atl.mindspring.net>...
NIBRAL1
>I'm hoping somebody in this group has some experience with Holley
>Carburetors.
Float adjustment will cause the fuel to 'leak' into the primary. I assume your
engine/tranny combo is a 1:1 and mounted on an angle. Adjust the primary
float slightly to lean, not parallel as the instructions suggest.
Crap in the needle seat will also cause the needle to not seat properly. So
depending upon how you cleaned the components prior to reassembly it is likely
you have a piece of fod in the needle seat.
Get the 5 gallon bucket of carb cleaner from NAPA. Break down your carb and
soak all the parts for an hour. Clean off the old gasket residue with a brass
brush and use compressed air to clean/dry all the pieces. DO NOT use cloth or
paper towels this is a sure way to get some thread or shread of paper into a
chamber and screw things up. Follow the reassembly instructions. Tip: place
gaskets on bowel bolts prior to putting them in place. (this prevents you from
dragging pieces of the gaskets through the holes that the threads of the bolts
may take off.) Ta Da! I really like tada. You should have a working carb
again.
New Holley marine - 'marine' being the operative word - are $600 - $700. At
$500 you have a bargin, rebuild, or a car unit, the latter being unacceptable
for your application.
Typical bench time is 2 hours for a rebuild.
$80/ hr x 2 = $160 +
Trick kit @ $50
Total for a rebuild - $210 give or take $50 depending upon area and sales tax.
ttfn
nibral1