Bowgus wrote:
Loping might indicate burnt valves ... a long ago best forgotten experience
with Firebird 400.


Ah, yes....the GM 400!

I had a tune-up done on it about a year ago. That included plugs, plug
wires, distributor cap, and rotor. Years ago, I bought a kit that
replaces points with an electronic unit. It doesn't replace the
distributor, just the points.

I bought a Holley carb kit and rebuilt it yesterday. No help.

Probably 6 years ago, the fresh water pump's impeller basically fell
apart. The boat overheated to the point that smoke was billowing out
the exhaust. I can't remember exactly when it started running bad, but
it was sometime after that happened (maybe the next summer). I'd think
if I had hurt a head gasket or warped a head, I'd have had problems
soon after the time I overheated it, not a year later.

I have checked the timing numerous times (maybe once per year). I
can't check it now because I can't get it started.

During the time I've been having problems with it, while running in the
driveway the boat "lopes" like it has a big cam in it. I've been told
that's an indication of a vacuum leak. That, combined with how it runs
when cold, combined with how it's now blowing fuel & exhaust out the
carb make friends of mine think its a head or head gasket problem. But
there's not water in the oil. Could this still be my issue?

You got to do the basics first:
compression and cylinder leakdown test
check camshaft timing, chain maybe worn out and jumped.

wrote in message
oups.com...
Hello,

I have an '88 Supra with a PCM Ford 351-Windsor engine.

I've been having problems with the engine in my boat for a few years.
For the first 20-30 minutes in the water, the thing runs like doo-doo.
It spits & sputters and barely gets on plane. After a while, the
engine gradually smoothes out. Eventually, the thing runs fine. I've
tried many things, including replacing the coil, replacing the points
with an electronic unit, replacing the fuel filter, and checking the
fuel pump.

I tried starting the boat for the first time since November. Now it
won't start at all. Instead, fluid is being spit out of the carb.
Also, while cranking, smoke (exhaust?) is coming out of the exhaust.
Occasionally it tries to fire up, but just spits a lot of fluid (gas?)
out.

Does anyone have any ideas what's wrong?

Thanks,

Donald

Woodchuck wrote:
You got to do the basics first:
compression and cylinder leakdown test
check camshaft timing, chain maybe worn out and jumped.

NOW you're on the right track.

The problem is that somewhere in your intake system there is a leak.
Heres how to test for it. Put the earmuffs on the engine have a can of
starting fluid handy. While your attempting to start the engine, spray the
starting fluid lightly into the carb to help it start. Once it starts,
and is running, spray the starting fluid around the edge of the carb, and
the intakes. Spray it on all surfaces on the top of the engine that are
not electrical. When you hit the right spot, you will notice an instant
rise in engine RPM. To confirm, simply spray that area again. Once
located, you will know which gasket or part you will have to replace. Your
simptoms are typical with an air leak in the intake causing a too lean
condition.

IMHO
Jack

wrote in message
oups.com...
Hello,

I have an '88 Supra with a PCM Ford 351-Windsor engine.

I've been having problems with the engine in my boat for a few years.
For the first 20-30 minutes in the water, the thing runs like doo-doo.
It spits & sputters and barely gets on plane. After a while, the
engine gradually smoothes out. Eventually, the thing runs fine. I've
tried many things, including replacing the coil, replacing the points
with an electronic unit, replacing the fuel filter, and checking the
fuel pump.

I tried starting the boat for the first time since November. Now it
won't start at all. Instead, fluid is being spit out of the carb.
Also, while cranking, smoke (exhaust?) is coming out of the exhaust.
Occasionally it tries to fire up, but just spits a lot of fluid (gas?)
out.

Does anyone have any ideas what's wrong?

Thanks,

Donald

"Jack" wrote in message
ink.net...
The problem is that somewhere in your intake system there is a leak. Heres
how to test for it. Put the earmuffs on the engine have a can of
starting fluid handy. While your attempting to start the engine, spray
the starting fluid lightly into the carb to help it start. Once it
starts, and is running, spray the starting fluid around the edge of the
carb, and the intakes. Spray it on all surfaces on the top of the engine
that are not electrical. When you hit the right spot, you will notice an
instant rise in engine RPM. To confirm, simply spray that area again.
Once located, you will know which gasket or part you will have to replace.
Your simptoms are typical with an air leak in the intake causing a too
lean condition.

IMHO
Jack

You can also do this with a can of propane and an old torch head with a
section of host hooked to the top of if. Just screw off the flame head of
the torch and connect the hose. This method will eliminate flammable fluids
sitting on the engine (until they evaporate) and the good chance of a fire.
If you do get flame flair up just turn off the torch head be sure to have
the torch set to a very low flow. It works quite nicely. Good luck and
make sure somebody is sitting next to the key just incase you need to shut
it down right away.



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