Idled normal, then high, after 3 min varied up and down, @ 5 minutes it stalled

stewfish1818

Seaman Apprentice
Joined
Jul 14, 2010
Messages
42
SEE VIDEO soon

The big question is why would it idle fast? slow = bag gas situation, bag electric situation, etc....

See video of the rough idle here, I thought water in the gas at first butit seems a little different because of the high RPM
http://www.youtube.com/watch?v=zxGDh_dw4EM&feature=plcp

1990 Johnson 150 - VJ150TXESB

My boat was not running well it would start up and go to 15 mph then die, eventually it would not start. We got a tow home. Fuel seemed to be the problem.

What I have done to test things:
1.) Changed the spark plugs
2.) Changed fuel filters
3.) hooked up to external tank.
4.) changed the gas line and bulb
5.) Cleaned the newly rebuilt carbs just encase there was a clog.
6.) Changed the one way puffer from the engine to the fuel pump which controls the speed of the pump.
7.) Ran the full pump discharge into a milk jug to see if when turning the key the pump would put out gas. I would say it put out a tablespoon-ish or more amount of gas per squirt
8.) Stator has correct Ohms while not running
9) Has spark, but may be intermittent.....???

Gas did squirt out of the fuel pump while cranking it for just second

I put a new fuel pump in 100 to 200 hundred hours ago; is there something that could be causing the fuel pumps to go bad so fast? Although last time it just wouldn't start, which made it easy to narrow down to the fuel pump. The mechanic is booked up for months.
 

stewfish1818

Seaman Apprentice
Joined
Jul 14, 2010
Messages
42
Re: Idled normal, then high, after 3 min varied up and down, @ 5 minutes it stalled

SEE VIDEO soon

The big question is why would it idle fast? slow = bag gas situation, bag electric situation, etc....

See video of the rough idle here, I thought water in the gas at first butit seems a little different because of the high RPM
http://www.youtube.com/watch?v=zxGDh_dw4EM&feature=plcp

1990 Johnson 150 - VJ150TXESB

My boat was not running well it would start up and go to 15 mph then die, eventually it would not start. We got a tow home. Fuel seemed to be the problem.

What I have done to test things:
1.) Changed the spark plugs
2.) Changed fuel filters
3.) hooked up to external tank.
4.) changed the gas line and bulb
5.) Cleaned the newly rebuilt carbs just encase there was a clog.
6.) Changed the one way puffer from the engine to the fuel pump which controls the speed of the pump.
7.) Ran the full pump discharge into a milk jug to see if when turning the key the pump would put out gas. I would say it put out a tablespoon-ish or more amount of gas per squirt
8.) Stator has correct Ohms while not running
9) Has spark, but may be intermittent.....???

Gas did squirt out of the fuel pump while cranking it for just second

I put a new fuel pump in 100 to 200 hundred hours ago; is there something that could be causing the fuel pumps to go bad so fast? Although last time it just wouldn't start, which made it easy to narrow down to the fuel pump. The mechanic is booked up for months.


UPDATE:
I started it back up for a friend to listen, the floats were empty since my first post here about 3 hours ago, so I must have ran the float down. After 3 minutes it started to rev of to 2000+ and then varied in RPM a little every 10 seconds. It then threw an alarm at five minutes and I shut it off.

I'm thinking the fuel pump is shotty and will get a little pressure but not enough when it really needs it

We did take out the spark plug and it did line up with TDC on the fly wheel, so that seems correct like I thought.

Thoughts anyone?
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: Idled normal, then high, after 3 min varied up and down, @ 5 minutes it stalled

cant be of much help on a big hp motor, but can you raise the remote tank above the level of the top carb for a gravity feed? just to see if there is any change?
 
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