Outboard revs up then dies
 

Wierd thing happened this weekend.

We had been running for quite a long time on the lake. We had probably been
cruising along for about 3 hours, with a couple of stops. I had started out
with a full tank of gas.

At about 3/4 of a tank, the motor did a weird thing. We were running at WOT
at about 4200 rpm when it suddenly had more power, went to about 4400rpm for
a second or two, then the engine slowly died.

It tried to start a couple of times. It'd idle, but when the throttle was
pushed forward it'd die.

The motor wasn't hot.

We ate lunch for about 20 minutes. Started the engine back up and cruised
towards the marina. It died again in the same manner.

Replaced the fuel filter at the Marina, but the problem came back later in
the day. The fuel filter we replaced looked fine, but it was the only thing
I could think of trying out there.

Water is pumping through the engine. I installed a new impeller last year.

I rebuilt the fuel pump at the beginning of last season. When I rebuilt the
fuel pump, I checked compression and it was good to great on all cylinders.

Over the winter I drained the fuel tank. I didn't figure on a condensation
problem as this is Arizona. Filled it with a fresh full tank of gas this
year.

We had pumped the bulb when it died. The bulb still had gas in it and would
pump up hard easily. Still wouldn't start.

When I would accelerate, the bulb would go soft but soon harden back up
again.

It's a 1998 Force 75hp 2-stroke.

It happened five times over the course of the weekend. Not at any serious
times luckily.

Any ideas what might be causing this?



TIA,

Buster

Check all you fuel lines for cracks, especially near the clamps. Its normal
for the bulb to go soft when accelerating.


"Buster" wrote in message
...
Wierd thing happened this weekend.

We had been running for quite a long time on the lake. We had probably
been
cruising along for about 3 hours, with a couple of stops. I had started
out
with a full tank of gas.

At about 3/4 of a tank, the motor did a weird thing. We were running at
WOT
at about 4200 rpm when it suddenly had more power, went to about 4400rpm
for
a second or two, then the engine slowly died.

It tried to start a couple of times. It'd idle, but when the throttle was
pushed forward it'd die.

The motor wasn't hot.

We ate lunch for about 20 minutes. Started the engine back up and cruised
towards the marina. It died again in the same manner.

Replaced the fuel filter at the Marina, but the problem came back later in
the day. The fuel filter we replaced looked fine, but it was the only
thing
I could think of trying out there.

Water is pumping through the engine. I installed a new impeller last year.

I rebuilt the fuel pump at the beginning of last season. When I rebuilt
the
fuel pump, I checked compression and it was good to great on all
cylinders.

Over the winter I drained the fuel tank. I didn't figure on a condensation
problem as this is Arizona. Filled it with a fresh full tank of gas this
year.

We had pumped the bulb when it died. The bulb still had gas in it and
would
pump up hard easily. Still wouldn't start.

When I would accelerate, the bulb would go soft but soon harden back up
again.

It's a 1998 Force 75hp 2-stroke.

It happened five times over the course of the weekend. Not at any serious
times luckily.

Any ideas what might be causing this?



TIA,

Buster

For whatever reason you are running out of gas. It revs just as it starts
to run out of fuel in the carbs and the engine runs lean for a second or so
and then dies.

Change the pump bulb assembly as a starting point. These can go bad and
cause this problem.
If that does not solve it - Check your fuel filter again. You may have
picked up more trash from the tank.
Last clean the carbs good.

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com

-
"Buster" wrote in message
...
Wierd thing happened this weekend.

We had been running for quite a long time on the lake. We had probably
been
cruising along for about 3 hours, with a couple of stops. I had started
out
with a full tank of gas.

At about 3/4 of a tank, the motor did a weird thing. We were running at
WOT
at about 4200 rpm when it suddenly had more power, went to about 4400rpm
for
a second or two, then the engine slowly died.

It tried to start a couple of times. It'd idle, but when the throttle was
pushed forward it'd die.

The motor wasn't hot.

We ate lunch for about 20 minutes. Started the engine back up and cruised
towards the marina. It died again in the same manner.

Replaced the fuel filter at the Marina, but the problem came back later in
the day. The fuel filter we replaced looked fine, but it was the only
thing
I could think of trying out there.

Water is pumping through the engine. I installed a new impeller last year.

I rebuilt the fuel pump at the beginning of last season. When I rebuilt
the
fuel pump, I checked compression and it was good to great on all
cylinders.

Over the winter I drained the fuel tank. I didn't figure on a condensation
problem as this is Arizona. Filled it with a fresh full tank of gas this
year.

We had pumped the bulb when it died. The bulb still had gas in it and
would
pump up hard easily. Still wouldn't start.

When I would accelerate, the bulb would go soft but soon harden back up
again.

It's a 1998 Force 75hp 2-stroke.

It happened five times over the course of the weekend. Not at any serious
times luckily.

Any ideas what might be causing this?



TIA,

Buster

"Buster" wrote in message
...
Wierd thing happened this weekend.

[snip]

Its running out of fuel. The increased power is from leaning out, and then
it simply dies from fuel starvation.

Since it just came up on you, I suspect some dirt in the carb(s) or some
other fuel blockage.

Good luck.

--
-Netsock

"It's just about going fast...that's all..."
http://home.columbus.rr.com/ckg/

Thanks, I'll try all those things. I'll be replacing the fuel hose/bulb
assembly next trip.

Actually, I just remembered something. I was on two lakes this weekend.
Roosevelt and Apache in Arizona. The first day was on Roosevelt, where
these problems occured. The last time it happened, we took some carb
cleaner and sprayed it into the carb while the engine was running.

After that I trailered over to Apache lake and the problem never cropped up
again there. Apache is a much smaller lake though, so I didn't get the
running time like I did on Roosevelt.

I figured it was something in the fuel system, but wanted a second opinion.

I guess my checks/fixes from here a
1. Replace fuel line/bulb.
2. Check vent on fuel tank.
3. Check fuel hoses under the cowl.
4. Check pickup in fuel tank
5. Clean/rebuild carb?

Is it ok to run something like Berrymans 44k fuel system cleaner through the
tank on a 2-stroke?


Thanks,
Buster


"Netsock" wrote in message
...

"Buster" wrote in message
...
Wierd thing happened this weekend.

[snip]

Its running out of fuel. The increased power is from leaning out, and then
it simply dies from fuel starvation.

Since it just came up on you, I suspect some dirt in the carb(s) or some
other fuel blockage.

Good luck.

--
-Netsock

"It's just about going fast...that's all..."
http://home.columbus.rr.com/ckg/

Buster wrote:
Wierd thing happened this weekend.

We had been running for quite a long time on the lake. We had probably been
cruising along for about 3 hours, with a couple of stops. I had started out
with a full tank of gas.

At about 3/4 of a tank, the motor did a weird thing. We were running at WOT
at about 4200 rpm when it suddenly had more power, went to about 4400rpm for
a second or two, then the engine slowly died.

It tried to start a couple of times. It'd idle, but when the throttle was
pushed forward it'd die.

The motor wasn't hot.

We ate lunch for about 20 minutes. Started the engine back up and cruised
towards the marina. It died again in the same manner.

Replaced the fuel filter at the Marina, but the problem came back later in
the day. The fuel filter we replaced looked fine, but it was the only thing
I could think of trying out there.

Water is pumping through the engine. I installed a new impeller last year.

I rebuilt the fuel pump at the beginning of last season. When I rebuilt the
fuel pump, I checked compression and it was good to great on all cylinders.

Over the winter I drained the fuel tank. I didn't figure on a condensation
problem as this is Arizona. Filled it with a fresh full tank of gas this
year.

We had pumped the bulb when it died. The bulb still had gas in it and would
pump up hard easily. Still wouldn't start.

When I would accelerate, the bulb would go soft but soon harden back up
again.

It's a 1998 Force 75hp 2-stroke.

It happened five times over the course of the weekend. Not at any serious
times luckily.

Any ideas what might be causing this?



TIA,

Buster



I am no expert - I run my little 7.5 out of fuel after each use. I
unplug the fuel line till it dies. Right before it dies it will increase
rpm's like you mention. So to me it sounds like it is starving for fuel.

Capt Jack R..

I would not use anything not desiged for a 2 stroke.
You stand a chance of the oil not mixing properly and blowing the engine.

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com

-
"Buster" wrote in message
...
Thanks, I'll try all those things. I'll be replacing the fuel hose/bulb
assembly next trip.

Actually, I just remembered something. I was on two lakes this weekend.
Roosevelt and Apache in Arizona. The first day was on Roosevelt, where
these problems occured. The last time it happened, we took some carb
cleaner and sprayed it into the carb while the engine was running.

After that I trailered over to Apache lake and the problem never cropped
up
again there. Apache is a much smaller lake though, so I didn't get the
running time like I did on Roosevelt.

I figured it was something in the fuel system, but wanted a second
opinion.

I guess my checks/fixes from here a
1. Replace fuel line/bulb.
2. Check vent on fuel tank.
3. Check fuel hoses under the cowl.
4. Check pickup in fuel tank
5. Clean/rebuild carb?

Is it ok to run something like Berrymans 44k fuel system cleaner through
the
tank on a 2-stroke?


Thanks,
Buster


"Netsock" wrote in message
...

"Buster" wrote in message
...
Wierd thing happened this weekend.

[snip]

Its running out of fuel. The increased power is from leaning out, and
then
it simply dies from fuel starvation.

Since it just came up on you, I suspect some dirt in the carb(s) or some
other fuel blockage.

Good luck.

--
-Netsock

"It's just about going fast...that's all..."
http://home.columbus.rr.com/ckg/