TWL: gas engine not starting
My new to me Tollycraft 26 could be the source of a daily inquiry of the
list, but I will try to limit my appetite for help and advice. However,
not being able to start the engine seriously cuts back on boating
enjoyment so here goes.
I have not been able to get my single gas inboard started this spring. I
bought the boat in July and it had been sitting for at least two years.
The engine, a Crusader 270 (Chevy small block), ran pretty well last
fall. I ran the old fuel out of the tanks, refilled before layup, added
Stabil and changed the water separator/fuel filter. I ran the boat
enough to insure the carb had stabilized fuel in it.
After launching the other day I brought fresh batteries aboard and tried
to start the engine. She turned over smartly, but would not start. I
checked the fuel valves and vents, OK. I checked for spark,OK. I poured
a half-ounce of gas into the carb. Started and ran a few seconds. Hmmm.
It seems the ignition system is OK, so it's a fuel thing I suppose.
Since I had just changed the fuel filter, I didn't wish to change it
again. Instead I tried hooking an outboard tank filled with straight gas
to the inlet side of the fuel pump. No go. I then disconnected the fuel
line between the fuel pump and the carb to check the fuel pump. It does
pump while cranking, but I got some water and crud in the first few
spurts. I checked the filter in the carb and it was quite dirty. I
changed it and put a new fuel line between the pump and the carb. Still
wont start. The fuel pump is a Carter that has a sight tube that will
fill with fuel if the diaphragm goes, it's dry. The only test for the
fuel pump in the service manual is a pressure test while running. It
does pump while cranking, but I am not sure about adequate volume or
pressure. Seems OK.
I am thinking I must have crud and water in the carb, or a problem with
the needle valve or float. It's a Rochester Quadrajet, and I don't feel
up to rebuilding it myself, but have a very tight boat budget (I spent
the kitchen money on the boat!). Can anyone think of anything to try
before taking the carb off? Am I correct to think that because it will
run a few seconds on gas poured into the carb that the ignition system
is OK?
I'm stumped. I'd sure appreciate any help.
Thanks,
Jack
MV Guambiana
Near the head of navigation on the Mississippi.
------ http://USFamily.Net/info - Unlimited Internet - From $8.99/mo! ------
<<<<<I have not been able to get my single gas inboard started this spring.
Jack,
I would try tapping the carb with a small brass hammer, or even a
screwdriver handle, right around where the fuel line goes in. Don't distort
it, just little love taps. A lot of times the needle valve will get stuck
in the closed position. (gas in carb, float in shutoff position. gas
evaporates, float stays put) A lot of times a slight tapping will let the
float fall back down to the open position. If this fixes it, be leery.
Lots of time the needle valve will stick again. Probably at the worst
moment, such as docking in a wind.
Had this happen on a Dodge truck recently (had little use for 2 years by the
PO). It would stick intermittently in the morning for about the first 2000
miles. Seems ok now. I did run some Gumout cleaner through the fuel
system. If this does the trick, maybe you'll feel better about spending $
for a carb rebuild (or de-gum) instead of playing Guess and By Golly with
parts.
Good Luck,
Chris
You are correct, sir... but rebuilding a Qjet isn't hard at all. Just get
the kit and it should have instructions. Be sure to do it on a workbench or
someplace where you won't lose any small parts. I think it only has about a
dozen parts in the kit.
You could try spraying a can of Gumout in there while cranking... it'll run
on the Gumout and it'll clean it out well. Spray it into the throttle
bodies, and the vent tube that's sticking up. If that doesn't work, tear
into it and you'll be surprised how easy it is to rebuild.
Keith
__
Always try to keep the number of departures you make from your slip equal to
the number of returns you've made.
----- Original Message -----
<snip>
I am thinking I must have crud and water in the carb, or a problem with
the needle valve or float. It's a Rochester Quadrajet, and I don't feel
up to rebuilding it myself, but have a very tight boat budget (I spent
the kitchen money on the boat!). Can anyone think of anything to try
before taking the carb off?
At 08:15 PM 4/17/03 -0500, you wrote:
You are correct, sir... but rebuilding a Qjet isn't hard at all. Just get
the kit and it should have instructions. Be sure to do it on a workbench or
someplace where you won't lose any small parts. I think it only has about a
dozen parts in the kit.
You could try spraying a can of Gumout in there while cranking... it'll run
on the Gumout and it'll clean it out well. Spray it into the throttle
bodies, and the vent tube that's sticking up. If that doesn't work, tear
into it and you'll be surprised how easy it is to rebuild.
Keith
Jack,
I hate to be the one to disagree with the above, but having rebuilt
probably 100 carbs of various types, even ones that were supposedly just
rebuilt by an amateur, I have to speak up here. While carb rebuilding to
someone with the right equipment, which includes not just a can of carb
spray but a proper soak tank, tools and an air compressor to allow blowing
out the passages, rebuilding a carb properly can have a lot of
pit-falls. Especially to someone who has never done one under proper
supervision. Lacking both the proper equipment and prior experience I
think having the carb professionally done is the right thing to do here.
Jim Alexander, Realtor
Vista 43
Port Charlotte, FL
I have to agree with Jim that successfully rebuilding a carburetor if you
have never done it before is not all that easy. The second issue is that a
no start condition is not normally associated with a carburetor. Once
someone has walked you through what is inside a carburetor and if you know
what you are looking for it is not rocket science. I can remember a 2 day
GM school on Quadrajets and I was not bored.
Frank Burrows
. but rebuilding a Qjet isn't hard at all.
-----Original Message-----
Keith wrote:
but rebuilding a Qjet isn't hard at all. Just get the kit and it should have
instructions. Be sure to do it on a workbench or
someplace where you won't lose any small parts. I think it only has about a
dozen parts in the kit.
REPLY
Having specialized in tinkering with Q-jets for about 9 years while racing on
older corvette I am inclined to agree that rebuilding one of these is not a
good idea for a beginner who has not done it before.
Furthermore, it is getting very difficult to find rebuild kits of
conventional carbs.
GM started the switch over to fuel injection back in the mid eighties.
My 1986 Buick had an electric Q-jet and by 1988 it was completely
electronic - throttle body injection.
Auto parts stores had to special order Q-jet carb kits since only specialty
shops bother to rebuild them.
regards
Arild
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Locally, a new Edelbrock copy of the old Carter 4 barrel cost the same as a
professional rebuild. In fact, the Edelbrock was labeled as a factory
rebuild, but was in fact new. The auto version has all the marine components
and is cheaper. With the carb professionally installed, the engine ran
better at low speed and was quieter. And now, I bought a diesel.
Ron Rogers
Annapolis, MD
{8^0)