boat still dieing out...please help

[kabo0ky]

ok guys please help me out. i'm a fairly new boater here. here is whats going on. i have a 91 force 70hp. when i'm at home it runs fine but as soon as i put her in the water the engine sounds like it wants to die out at idle. and when i give it gas it'll run for about a 3-4 minutes then die out and i can't start it again. here is what i've don't since the problem started. <br /><br />1. new fuel line<br />2. new primer bulb<br />3. rebuild carb<br />4. decarb<br />5. new plugs<br />6. new head gasket (since i notice #2 cylinder was clean and so was the plug)<br /><br />ok now the #2 cylinder is not wet anymore and the plug is dirty like the other two. i've done a compression test and #1 = 115 #2 = 110 #3 = 115.<br />What could i be missing?<br />please help

 

[scotiany]

Re: boat still dieing out...please help

What about changing the fuel pump diaphragm and gasket. If you have any hose left over from the fuel hose change, change the vacuum-pressure hoses on the fuel pump too.

 

[kabo0ky]

Re: boat still dieing out...please help

i'm sorry i forgot to mention...i changed out the diaphragm and the gasket already. but where is the vacuum-pressure hoses?

 

[scotiany]

Re: boat still dieing out...please help

Those are the 2 hoses that go from each chamber of the fuel pump to the engine. They power the diaphragm in the pump. About 3-4 inches long. Fuel hose will work as a replacement(at least on Chryslers).

 

[eurolarva]

Re: boat still dieing out...please help

When you did the compression test was it on a warm motor and were all the plugs out. Those numbers seem pretty low for a 91. I would expect to see numbers in the 130 range or higher. Your motor crapping out after 3 or four minutes. Are you sure water is circulating and it is not overheating? Other option is you got a bad coil or cd unit that is getting week and causes problems when motor is warm.

 

[kabo0ky]

Re: boat still dieing out...please help

well when i did the compression test the motor wasn't up to running temp. and i'm sure the water is circulating throught the motor. there is a strong stream of water pissing out the motor. how would i check the coil or the cd unit?<br /><br />thanks for the replys

 

[kabo0ky]

Re: boat still dieing out...please help

if the carb wasn't adjusted right will it cause the motor to die out like that?

 

[CoachHolland]

Re: boat still dieing out...please help

After the motor is warmed up, check the amount of spark getting to your plugs. You can do this with an ignition spark tester you can pick up at any auto store.<br /><br />Pull the wires, insert the tester and ground it. Turn it over and watch and wait for awhile to let the engine get warm and see if you're getting a good clean spark to all cylinders.<br /><br />If you're not getting much spark after the engine has warmed up, then likely the problem is in the CD unit.

 

[kabo0ky]

Re: boat still dieing out...please help

i'll do that as soon as i can...thanks

 

[kabo0ky]

Re: boat still dieing out...please help

ok i've tried the spark tester and all three plugs are getting good spark with a cold or hot motor. what less could be wrong? i have no idea. please help

 

[Oldsaltydog]

Re: boat still dieing out...please help

Given that your motor dies in water only, could there be some sort of obstruction in your exhaust system ? -- which shows up when there is water back pressure.

 

[kabo0ky]

Re: boat still dieing out...please help

how would i check the exhaust system?

 

[Oldsaltydog]

Re: boat still dieing out...please help

Visually, perhaps with the help of poking around gently with a piece of wire. You may have to take off the prop, should it be in the way.

 

[kabo0ky]

Re: boat still dieing out...please help

i can't seem to find anything in the manual about the exhaust system. someone please tell me how to check the entire exhaust system. like EBG said i might have a clogged exhaust which causes my motor to bog and die in the water. do i have to remove the prop and lower unit to check that?

 

[eurolarva]

Re: boat still dieing out...please help

When you pull motor out of the lake when after it is running are you seeing any oil gas mix coming out of the exhaust holes on the lower unit. IF so I would say your exhaust is not blocked. It will look like white frothy stuff coming out of the lower unit.. When motor dies does the fuel bulb for the gas can collapse or stay hard? Have you tried loosening or removing the gas cap on the gas can? Sounds to me if it isnt spark then your gas is not flowing freely or you have an air leak. <br /><br />When you pump on the bulb does it get hard? No gas coming out of the carbs during the pumping? <br /><br />I am probably being of little help here. Just maybe coming up with something that maybe you did not think of.

 

[kabo0ky]

Re: boat still dieing out...please help

i appreciate your input eurolarva. the primer bulb does stay hard. and when the motor does die out it is still hard. there is no gas pissing out the carb when the primer bulb in hard. when i bring the boat back out of the water i don't see oil or white stuff coming out of the lower unit. and i've try opening the gas cap when it dies but doesn't help. and also tried taking off the cowl and still the same.