Runs for 45min. then dies

motometer

Cadet
Joined
Aug 1, 2004
Messages
6
1968 85 hp johnson, Runs great for 45 min. at first when cold, then starts to lose power and keeps loseing untill it dies complety, you have about 3 min till it's gone, before it starts to lose power it soumds like it is missing.<br />Let sit for 20 min, then runs great for about 10 min. then starts to die again. ????<br />Water pump working, Clean carb. twice!!<br />new fual hose & bulb, check fuel pump ok, <br />Can a over heated engine slow to a stop like this then be ok in 20 min??<br />could be a coil braking down??<br />has anybode have this same problem<br />Please let me know<br />Thanks, :confused: <br /> <br /><br /> :confused:
 

Joe Reeves

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Feb 24, 2002
Messages
13,262
Re: Runs for 45min. then dies

Overheating could cause that problem but it wouldn't take 45 minutes for it to take effect.<br /><br />It sounds more like you might have a fuel restriction.... clogged fuel vent or if using a built in tank, a sticking anti siphon valve which is explained as follows.<br /><br />(Fuel Anti Siphon Valve)<br />(J. Reeves)<br /> <br />Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vaccum device attached to the powerhead. If the engine overheats, or if you have a fuel restriction, the warning is the same.... a steady constant beep.<br /> <br />NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models. <br /><br />The fact that a engine is not overheating, but the warning horn sounds off with a constant steady beep, and that the rpms drop drastically would indicate that the engine is starving for fuel due to a fuel restriction. Check the built in fuel tank where the rubber fuel line attaches to the tank fitting. That fitting is in all probability a "Anti Siphon" valve which is notorious for sticking in a semi closed position. It will be aluminum, about 2" long, and the insides of it will consist of a spring, a ball, and a ball seat. If this valve exists, remove it, knock out those inner components which will convert it to a straight through fitting, then re-install it. Hopefully that cures the problem.
 

motometer

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Aug 1, 2004
Messages
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Re: Runs for 45min. then dies

Hello Joe,<br />Thanks for your info, my boat has a portable tank with new hose and bulb<br />the bulb is hard when this problem starts I will go back and crush the bulb thinking it is out of gas but it's not helping it still dies.<br />Do you think it could be the power pack??<br />Thanks again<br />Glenn
 

reload

Petty Officer 1st Class
Joined
Jun 29, 2004
Messages
368
Re: Runs for 45min. then dies

motometer, I am having the same type trouble with a 9.9 hp evinrude. I have tryed everthing you spoke of. I was also thinking that maybe it was heat related. I noticed the other day that if I removed the cover when it first started acting up that it will keep running be not good. If I shut it off for 15 minutes it will run great for a while.<br /><br />Paul
 

motometer

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Joined
Aug 1, 2004
Messages
6
Re: Runs for 45min. then dies

Hi Paul,<br />Is your carb out of gas when this happens?<br />when you restart your engine after it has set a while is the carb empty when you crush the primer bulb, <br />I have notic mine is empty and I have to pump it back up<br />Please let me know if you find anything out. I would like to go boating this weeking Ha ha<br />Thanks <br />Glenn
 

reload

Petty Officer 1st Class
Joined
Jun 29, 2004
Messages
368
Re: Runs for 45min. then dies

I don't how to tell if the carb is out of gas. I do not have to crush the primer bulb to restart. Yours sounds like it has a restriction the fuel tank. Maybe it is dirt in the tank clogging the filter screen.<br /><br />Paul
 

motometer

Cadet
Joined
Aug 1, 2004
Messages
6
Re: Runs for 45min. then dies

I have went to my outboard dealer today he said check your coil it sounds like it is braking down. <br />The fuel tank and hose are new it should not have a fuel problem in that area but the carb is still enpty?? I have cleaned it twice and the needle holds with no leaks. It's crazy!!<br />I have a 1968 model 85 hp 4 cyl. it don't have a power pack<br />the newer models have a coil for each cyl.<br />he said if one coil goes down the other ones should keep the enging going not to die off just lose power<br />if you have a power pack on yours the dealer can check it out to see if it is braking down <br /><br />Glenn,
 

jsfinn

Lieutenant Junior Grade
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Nov 26, 2003
Messages
1,093
Re: Runs for 45min. then dies

motormeter,<br /><br />are you opening the vent on your gas tank?
 

motometer

Cadet
Joined
Aug 1, 2004
Messages
6
Re: Runs for 45min. then dies

That is the first thing I have checked<br />The old motor has a lot stuff to do (switches,levers) before you can start it.<br />I hade thought I forgot to open the vent when it starter to die
 

motometer

Cadet
Joined
Aug 1, 2004
Messages
6
Re: Runs for 45min. then dies

Say I think I have found the problem!!!<br />Who ever put the new distributor in never put a new condenser wire in It was shorting out under the rotor <br />I will try it out this weeking<br />Thanks for all yall' help<br />Glenn,
 
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