Took my boat out today. It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. Then it runs fine, starts fine, idles fine, high speed fine.
Then the other end again. I'm going to change the fuel filter on the motor
and see if that does it. After that, I guess it just has to go to the shop.
'89 Merc 4 cyl. 40 2 stroke.

Steve

On May 29, 11:41*pm, "SteveB" wrote:
Took my boat out today. *It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. *Then it runs fine, starts fine, idles fine, high speed fine.
Then the other end again. *I'm going to change the fuel filter on the motor
and see if that does it. *After that, I guess it just has to go to the shop.
'89 Merc 4 cyl. 40 2 stroke.

Steve

Possibly a vent clogged on the gas tank creating a suction and not a
freeflow on the fuel?

Tim wrote:
On May 29, 11:41 pm, "SteveB" wrote:
Took my boat out today. It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. Then it runs fine, starts fine, idles fine, high speed fine.
Then the other end again. I'm going to change the fuel filter on the motor
and see if that does it. After that, I guess it just has to go to the shop.
'89 Merc 4 cyl. 40 2 stroke.

Steve

Possibly a vent clogged on the gas tank creating a suction and not a
freeflow on the fuel?

Yes. Possibly the vent not opened. Possibly a clogged screen filter in
the gas can. Possibly a collapsing fuel line. Possibly a real tiny air
leak on the suction side. A larger air leak will stop fuel pumping all
together. Some outboards have a slow mode that restricts rpms if there
is an engine problem.
The best thing Steve can do is borrow or buy a gas tank with hose. That
will eliminate all off engine problems.

"SteveB" wrote in message
...
Took my boat out today. It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. Then it runs fine, starts fine, idles fine, high speed
fine. Then the other end again. I'm going to change the fuel filter on
the motor and see if that does it. After that, I guess it just has to go
to the shop. '89 Merc 4 cyl. 40 2 stroke.

Steve

Might try it again and when it dies during the problem, pull a couple plugs
and see if they're dry or wet.

"jim785" wrote in message
...
Tim wrote:
On May 29, 11:41 pm, "SteveB" wrote:
Took my boat out today. It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start
and
keep running. Then it runs fine, starts fine, idles fine, high speed
fine.
Then the other end again. I'm going to change the fuel filter on the
motor
and see if that does it. After that, I guess it just has to go to the
shop.
'89 Merc 4 cyl. 40 2 stroke.

Steve

Possibly a vent clogged on the gas tank creating a suction and not a
freeflow on the fuel?

Yes. Possibly the vent not opened. Possibly a clogged screen filter in the
gas can. Possibly a collapsing fuel line. Possibly a real tiny air leak on
the suction side. A larger air leak will stop fuel pumping all together.
Some outboards have a slow mode that restricts rpms if there is an engine
problem.
The best thing Steve can do is borrow or buy a gas tank with hose. That
will eliminate all off engine problems.

I checked the vent, and nearly unscrewed the cap. I need to take the hose
off, and check that all out. It had one loose hose clamp, which I
tightened. But the symptoms repeated. Buy a gas tank with a hose? I have
one. Do you mean buy a new one? How would that solve an engine problem?

Steve

"jim785" wrote


I mean a different one. New is good.
We haven't determined, yet, that you have an engine problem.
The symptoms you describe often are caused by problems with the tank or
hoses.
Worst case is you have an AUX gas tank and hose. That's not a bad thing.

Tank LOOKS fine. Not very old. Vent works, threads good. When I take the
hose off the barb at the engine connector and squeeze the bulb, full flow
pumps out with no resistance. I DO think, tho, that trying another hose
will be a test case. Maybe just borrow one from a friend. In the meantime,
I'll change that motor fuel filter, and check the snap connector that goes
into the motor. I really think it's probably something simple. Once I find
it, that is.

Steve

"SteveB" wrote in message
...

"jim785" wrote


I mean a different one. New is good.
We haven't determined, yet, that you have an engine problem.
The symptoms you describe often are caused by problems with the tank or
hoses.
Worst case is you have an AUX gas tank and hose. That's not a bad thing.

Tank LOOKS fine. Not very old. Vent works, threads good. When I take
the hose off the barb at the engine connector and squeeze the bulb, full
flow pumps out with no resistance. I DO think, tho, that trying another
hose will be a test case. Maybe just borrow one from a friend. In the
meantime, I'll change that motor fuel filter, and check the snap connector
that goes into the motor. I really think it's probably something simple.
Once I find it, that is.

Steve


Just an off chance, but I had a similar problem once. The snap connector at
the engine was not firmly attached and was leaking (sucking) air. Once I
found it and connected it properly, the engine ran fine.

Eisboch

SteveB wrote:
Took my boat out today. It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. Then it runs fine, starts fine, idles fine, high speed fine.
Then the other end again. I'm going to change the fuel filter on the motor
and see if that does it. After that, I guess it just has to go to the shop.
'89 Merc 4 cyl. 40 2 stroke.

Steve



80% of the time, the carb needs to be thoroughly cleaned when you have
symptoms like that.

"D K" wrote in message
...
SteveB wrote:
Took my boat out today. It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. Then it runs fine, starts fine, idles fine, high speed
fine. Then the other end again. I'm going to change the fuel filter on
the motor and see if that does it. After that, I guess it just has to go
to the shop. '89 Merc 4 cyl. 40 2 stroke.

Steve

80% of the time, the carb needs to be thoroughly cleaned when you have
symptoms like that.

Is that a thing that a decent DIYer can do?

Steve

On May 31, 10:45*am, "SteveB" wrote:
"D K" wrote in message

...

SteveB wrote:
Took my boat out today. *It ran fine at first, then has symptoms of fuel
starvation at high speeds, slowing to a crawl, and then hard to start and
keep running. *Then it runs fine, starts fine, idles fine, high speed
fine. Then the other end again. *I'm going to change the fuel filter on
the motor and see if that does it. *After that, I guess it just has to go
to the shop. '89 Merc 4 cyl. 40 2 stroke.

Steve

80% of the time, the carb needs to be thoroughly cleaned when you have
symptoms like that.

Is that a thing that a decent DIYer can do?

Steve

Yes, they're pretty simple. Get a manual for your engine and have at
it.