Mechanic stumped

[pigfish]

Have two 2003 ficht 225hp motors. Both run fine for about 20 minutes and then will shut down. No alarm or lights. Will not crank. After a wait of 20 minutes they will start up again and run for 15 minutes or so and shut down again. The slower I run the longer they will run before shutting down. Marine mechanic hooked up diagnostic computer to both motors and showed no problems. Sounds like the emm is shuting them, but both motors have the same problem? Mechanic is stumped. Please help.

 

[milmat1]

Re: Mechanic stumped

What things are common to both Engines??

 

[glennwolf]

Re: Mechanic stumped

I had a clogged foot valve or filter in my gas tank once that would do the same thing. Each time I got the motor started it would run for less time.

 

[Bifflefan]

Re: Mechanic stumped

A shot in the dark is a common electrical connection has gone bad. Corrosion causes heat and heat will add to the corrosion. Too much and loose the ability to let the electric flow. After it cools, it can flow again.

 

[pigfish]

Re: Mechanic stumped

I had a clogged foot valve or filter in my gas tank once that would do the same thing. Each time I got the motor started it would run for less time.

But would the motor turn over when you tried to restart? Mine are completely dead. Electronics work so batteries are ok but nothing but silence when keys are turned.

 

[Home Cookin']

Re: Mechanic stumped

fuel line wouldn't cause it not to restart.
when they die, is it sudden, like a pulled kill switch, or gradual, like running out of gas?
I'm betting on bad battery connection as said above. clean them and pliers tighten. better yet, test them on another battery. Those pins on the battery can corrode or break down inside the battery and you never know it--GM's are the worst.

Seems odd to have the starters fail and the engine power, since they are usually independent. If it were one motor I'd guess the solonoid and its ground.

Your ignition switch is also common to both--perhaps a short in there opens up with heat.
I've been chasing a ghost short in a motor and at one time thought it could be heat related in that it popped the fuse after running a while, but now I see that it is tied to rpm and not running time. It still could be a hot wire issue.

 

[seahorse5]

Re: Mechanic stumped

That is a common symptom of an EMM that is bad. It is surprising that both stop at the exact same time?

When they quit, are the gauges still on and do the self test lights flash and the horn sound a beep if you turn the key off then right back on?

If you turn the key off then right back on, do you hear the electric fuel pump run for about 10 seconds?

 

[pigfish]

Re: Mechanic stumped

fuel line wouldn't cause it not to restart.
when they die, is it sudden, like a pulled kill switch, or gradual, like running out of gas?
I'm betting on bad battery connection as said above. clean them and pliers tighten. better yet, test them on another battery. Those pins on the battery can corrode or break down inside the battery and you never know it--GM's are the worst.

Seems odd to have the starters fail and the engine power, since they are usually independent. If it were one motor I'd guess the solonoid and its ground.

Your ignition switch is also common to both--perhaps a short in there opens up with heat.
I've been chasing a ghost short in a motor and at one time thought it could be heat related in that it popped the fuse after running a while, but now I see that it is tied to rpm and not running time. It still could be a hot wire issue.

when it dies it is sudden like you turn off the key. no lights or alarms. total silence for 20 minutes or so until they let you restart, and then starts right back up.

 

[Silvertip]

Re: Mechanic stumped

The chance of both EMMs going south at the same time is very unlikely unless there is a common electrical issue between engines. Do both engines have their own battery? is there a dual battery switch in the system? Has some other creative wiring scheme been incorporated into the electrical system?