Engine quits abruptly

brokenbob

Recruit
Joined
Apr 18, 2009
Messages
3
Hey, people I have a 1994 force 120hp that, when running at high idle, the engine quits abruptly. Sounds like maybe a coil or spark plug wire maybe shorting out and the firing out of order. Need some suggests.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,842
Re: Engine quits abruptly

Welcome to iboats brokenbob.


Only at high idle?

Does it run alright at slow idle?

How about when underway?

Coil or plug firing intermittently will still fire when it is supposed to, and if only one is cutting out, the engine will usually keep running.

I suspect the kill switch wires in the controls. Possible to only be effected when in fast idle mode.

I would open the controls and inspect the wiring.
 

brokenbob

Recruit
Joined
Apr 18, 2009
Messages
3
Re: Engine quits abruptly

Thank Roscoe for replying,

This will happen if the engine is idling or in gear at an idle. It has happen when engine is running at any speed. Also, when idling, tied up at the dock. It also has a miss every so often like a plug is fouling out. Changed all plugs about two months ago.
 

brokenbob

Recruit
Joined
Apr 18, 2009
Messages
3
Re: Engine quits abruptly

Roscoe, I had glanced at you post and did not read it all, sorry. To answer all your questings.
1. It will stop at any speed.
2. Does it run alright at slow idle? No.
3. It will stop when at the dock or underway
4. It misses sporadically. When I say the engine stops, it sound like the engine miss fired and it stops without making
another revolution, but the engines starts up with ease.
5. The kill switch maybe the problem, the control has been hard to shift from reverse to forward sometimes and I have not checked that.
Have any other thoughts?
 

jason32038

Chief Petty Officer
Joined
May 25, 2009
Messages
555
Re: Engine quits abruptly

Sounds like a lean condition on a cylinder to me and or detonation from excess carbon or wrong spark plugs/timing.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Engine quits abruptly

Look for frayed or internally broken (wire broken inside the insulation) stator wires coming from under the flywheel. Look for frayed or broken trigger wires. Vibration can sporadically break contact. Check the terminal boards for loose connections
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,842
Re: Engine quits abruptly

Roscoe, I had glanced at you post and did not read it all, sorry. To answer all your questings.
1. It will stop at any speed.
2. Does it run alright at slow idle? No.
3. It will stop when at the dock or underway
4. It misses sporadically. When I say the engine stops, it sound like the engine miss fired and it stops without making
another revolution,
but the engines starts up with ease.
5. The kill switch maybe the problem, the control has been hard to shift from reverse to forward sometimes and I have not checked that.
Have any other thoughts?

This concerns me.

Everyone has make some great suggestions for you to check, but the abrupt stop is not normal.

Could be caused by a detonation, or timing issue, possibly caused by a broken flywheel key.

Lets hope it is something "that easy and cheap."
 
Top