motor dies after warm

[chief Bert]

I own a 1978 240 OMC I changed the piont cap rotor condesor and coil But after she runs on the lake for 20 minutes she dies acts like it runs out of gas but when I try and start it acts like the battery is dead I let it sit 30 minutes and she fires up ?

 

[Don S]

Re: motor dies after warm

Are you sure you're not overheating? That would make it hard to start (like a dead battery) timing and dwell may also be off. Did you set the dwell on the points or just use a feeler gauge?<br />May also have a plugged up fuel vent which would cause the "Run our of gas feeling" After 30 minutes air would get past the plug and you would be good for another 20 minute run.

 

[Boatist]

Re: motor dies after warm

I would love to now why you change all that stuff?? Did you have this problem before you changed all that?? If this is a new problem then I suppect the dwell is off and the motor is timed to far before top dead center. When timed to fast when engine is hot will fire to early before piston reaches the top so motor will try to turn backwards so started very slow like with a dead battery.<br /><br />Also did you replace with OEM parts or with the "Better than oem" Crap??

 

[DHPMARINE]

Re: motor dies after warm

OMC ? What color is the engine oil ?How full is the crankcase ?<br /><br />DHP

 

[chief Bert]

Re: motor dies after warm

the issue started before I changed all this so I checked the cap and it was cracked the points were changed along with the coil and condensor because if i am going to change one they all got it and I used the feeler guage

 

[waterone1@aol.com]

Re: motor dies after warm

After you double check the timing and dwell, I suggest that you make a lake run with the fuel cap off or loose (use common sense so you don't get water or crap in the tank) and see if the problem goes away (clogged vent line as Don suggested). By the way, when you say that it acts like it is "running out of gas" does that mean that the engine looses rpms,boggs down and dies ? Or is it a quick die, like turning off the key ?

 

[Scaaty]

Re: motor dies after warm

Take a second look at that point gap...and points...had a similar prob and drove me nuts. Found the Points were barely opening, and would just quit after 20 minutes. Somehow had closed up, and fried the contacts. Think it might have been heating up the coil and somehow losing spark. Dead in the water, barley turn over, but would start in 1/2 hour like nothing happened.

 

[Scaaty]

Re: motor dies after warm

Fuel pump could be going bad also...when it does this again, pull the carb arrester and pump the throttle and look for accelerator pump gas flow

 

[marinemech]

Re: motor dies after warm

check all gear oil

 

[Boatist]

Re: motor dies after warm

When it dies and will not restart and sounds like the battery is dead try this. First make sure you do not have any gas fumes in the boat but then pull the coil wire out of the center of the distributor and ground to the block. If the starter turns motor over normal then the problem has something to do with the Points Gap / Dwell / Timing.<br /><br />If it still turns over slow then check block Temperature. See if you can put your finger on it for 2 seconds with out getting burnt.

 

[chief Bert]

Re: motor dies after warm

Ok this is driving me NUTS i can run this motor hooked up to a hose for hour no issues back to the lake and about 20 minutes she dies ???

 

[Don S]

Re: motor dies after warm

That's because you aren't using much fuel because you don't have a load on the engine.<br />Did you check by pulling the cap off the tank, did you do anything with the previous suggestions?

 

[trog100]

Re: motor dies after warm

the battery acting like its dead fits with overheating on the lake.. the enigne just dieing after half an hour fits with blocked fuel tank vent..<br /><br />should be easy to find out which.. try to burn your hand on the engine and pull the filler cap off.. <br /><br />trog100<br /><br />ps.. there is a big difference tween burning one gallon an hour on the muffs and ten gallons an hour on the lake..